High energy fuel consisting of a mixture of bridged polycyclichydrocarbons and methods



United States Patent HIGH ENERGY FUEL CONSISTING OF A MIX- TURE 0FBRIDGE!) POLYCYCLICHYDROCAR- BONS AND METHODS Eldon E. Stahly,Birmingham, Mich assignor, by mesne assignments, to Sinclair Research,Inc., a corporation of Delaware No Drawing. Filed Aug. 17, 1959, Ser.No. 833,996

24 Claims. (Cl. Git-35.4)

This invention relates to mixtures of position isomers of bridgedsaturated polycyclic hydrocarbons having various uses, but particularlyas a high energy fuel for jet, turbojet, rocket, missile and otherreaction engines; to processes for forming such hydrocarbon mixtures: tointermediate mixtures useful in said processes; and to operation of jetengines by combustion of said hydrocarbon mixtures therein.

Other secondary uses for my mixture of compounds in the lower viscosityranges include heat transfer fluids, hydraulic fluids, and transfonneroils. In the higher viscosity ranges and particularly includingpolymeric forms of my compounds, they are also useful as new highstability lubricants. They are also useful as plasticizers, extendersand softeners of elastic and plastic materials.

Hydrocarbon mixtures of my compounds having from 14 to 30 carbon atomsare usefully liquid over wide temperature ranges, they have relativelyhigh boiling points and relatively low depressed freezing points. Moreparticularly, hydrocarbon mixtures hereof have a high energy content,that is, a high B.t.u. value per gallon and relatively high density orspecific gravity. This combination of characteristics makes the presenthydrocarbon mixture of position isomers outstanding for use asjet fuels.

My compositions for jet fuel use comprise a mixture my position isomersof hydrocarbon compounds comprising di-(lower alkylcyclohexyDalkanes andlower alkylcyclohexyl-cyclohexylalkanes having the following formula:

in which R and R are each linear or branched lower alkyl radicals having1 to 13, preferably 1 to 5 carbon atoms; Y is an alkylene bridge radicalhaving 1 to 13 carbon atoms of either linear or branched chainconfiguration; m is an integer from 1 to 3 and n is an integer from 1 to4,

I H I represents a saturated benzene (cyclohexyl) nucleus, and the totalcarbon atom content of my compounds, when they are liquid, ranges from14 to about 30 carbon atoms. At higher carbon atom contents, thecom-pounds can be viscous liquid to solid mixtures.

The specific gravity of such liquid mixtures will generally exceed about0.8, and by the term high gravity as used herein, I mean a liquid havingthis minimum Or higher gravity. The B.t.u. value will usually exceedabout 125,000 B.t.u. per gallon and by the term high energy as usedherein, I mean :a combustible mixture having this minimum or higherB.t.u. value. For instance, the gravity of the jet fuels hereof usuallylie in the range of about 0.85 up to about 0.91, and the B.t.u. valuepreferably ranges from about 132,000 up to about 140,000 B.t.u. pergallon.

Fatentecl Oct. 1, 1963 In the hydrocarbon formulae hereof, the loweralkyl radicals R and R include C to C alkyl radicals such as methyl,ethyl, propyl, isopropyl, n-butyl, secbutyl, tert-butyl, n amyl, theiso-amyls, tert-arnyl, n-hexyl, the iso-hexyls, rtert-hexyl,diisopropyl, n-heptyl, isoheptyl, dir-sobutyl, 2-ethylhexyl,triisopropyl, n-nonyl, n-dodecyl, tetraisopropyl, triisobutyl, tridecyland other isomeric forms of these and R and R may be selected to beeither the same or different alkyl radicals.

In the hydrocarbons Formulae I through IX herein, the term alkylene orbridge radical Y includes all divalent acyclic C to C hydrocarbonradicals which bridge the two ring hydrocarbon radicals through the samecarbon atom or through different carbon atoms of the bridge Y and thusthe term alkylidene bridge Y defines a specific type of alkylene bridgeY.

In the hydrocarbon formulae cal Y may be illustrated by the followingformulations: methylene (CH ethylidene (=CHCH ethylene (-CH CHn-propylidene-l,l (=CHCH CH propylidene-2,2

hereof, the alkylene radil (CH CH3) propylene-1,2

(CH2(|JHCH3) propylene-1,3 (CH CH CH n-butylidene-1,l

(=CHCH CH CH isobutyl-idene-l'd (=CHCH(CH n-butylidene-2,2

(CH: C C'HzC Ha) n-butylene- 1,2

(OH2(l1HCHzCHa) n-butyl ene-l 3 (CH2 C H2 (,3 HCHa) isobutylene-1,3

0 H; V (-0H2CHCH2-) n-butyiene-2,3

(oHac int inoHa) n-pentylidene-1,1 (=CH(CH CH isopentylene-1,4

CH3 (OH2O HCHzCH2) n-pentylene-LZ (CHz?H(CHz)rCHs) n-hexylidene,n-hexylene-l,2, n-hexylene-l,3, n-hexylene- 1,4, n-hexylene-l,5, nhexylene-h'o, isohexylidenes, isohexylene-1,2, n-heptylidene,iso-ootylene-1,7, n-nonylidene, n-undecylidene, n-dodecylidene, andn-tridecylidene, including the various isomeric configurations of thesecompounds and homologues thereof having not more than 13 carbon atoms.

As formed by the methods as further described below such compounds willconstitute mixtures of numerous position isomers. For instance, in itssimplest form, where R=methyl, Y=methylene, m=1 and n=l, there will beat least 3 isomers of the several position types, but where m=l and11:2, there will be 6 position isomers, and where m=2 and 11:3, therewill be at least 36 position isomers. Of course where position isomerismcan result by variation of attachment of the ring nuclei to the alkylenebridge -Y then the number is considerably greater. The number furtherincreases with the variations in number and isomeric form among thealkyls. Moreover, as described below some of the cyclic radicalsthemselves are often derived from hydrocarbon fractions comprisingmulticomponent mixtures of alkyl substituted aromatic hydrocarbons fromwhich the final products hereof may be made, and, as thus formed, maycomprise mixtures of even greater complexity.

Thus my compositions comprise mixtures of a great number of positionisomers as well as homologues, as formed by the methods described below.This is desirable because as a mixture it allows the production forexample, of a jet fuel usually in liquid form when the carbon atomcontent is in the range of 14 to 30, a product of relatively highboiling point, relatively constant high gravity, and at moderatetemperatures, fluid viscosity. My mixture of numerous position isomershas also a relatively low depressed freezing point, often as much as 50C. below that of a corresponding pure isomer.

A further advantage of my mixture of position isomer compounds is thatthey may be produced to desirably close specifications, most desirablefor a jet fuel, not withstanding that they are a mixture of so manydistinct compounds, by methods which in themselves are highly economic.

As pointed out, the total number of carbon atoms is in the range of 14to about 30 where my compounds are used as normally liquid fuels atambient temperatures. Within these limits, the alkyl and alkylenesubstitutions of the benzene radicals will be selected in number andsize whereby liquid compounds are produced. For example, the alkylenebridging group can be reduced in carbon chain size, preferably in therange from 1 to 5 carbon atoms, while simultaneously the alkyl groupsattached to the ring can be increased in number and size, and viceVersa, for purposes of maintaining the size of the compounds within the14 to about 30 carbon atom limits to define a liquid fuel.

Outside of these limits my mixture of isomeric compounds can be viscousoil or a solid mixture of position isomers. These too can be used asfuel, but for liquid fuel use may have to be heated to reduce theirviscosity or even melted. These, including the normally liquid types,have other uses as stated above.

An advantage of the variation of my liquid fuel in the range 14 to about30 carbon atoms, and the variation to produce a large number of positionisomers in each product is that my mixture is usually or can be maderelatively uniform with respect to the number of carbon atoms of eachproduct in any of its uses. For instance as set forth in many of theexamples below each product may be composed of a mixture of compounds ofthe same number of carbon atoms. When the ring substituents are derivedfrom a commercial mixture of C to C aromatics, the total carbon atom ofcompounds count in the several compounds of the resulting mixture wouldgenerally vary only in this corresponding narrow range. Of course, sidereactions such as further condensation, produce compounds having ahigher number of carbon atoms such as the tricyclic or polycyclicalkanes, for example, the di-(alkylcyclohexyl-rnethyl)-alkylcyclohex-'ane, di-(alkylcyclohexyl-ethyl)-alkylcyclohexane, and the like. Thepolymeric multi-bridge and multi-ring compounds being higher boiling arereadily separated by distillation. .Where a wide boiling range fuel isnot objectionable and where the final products are highly viscousliquids or even solids, such heavy ends need not be removed from thefuel.

These heavy ends may be illustrated by the formulae:

til

4 .r on

III

wherein R R m and n have the same significance as given in Formula I,and Y may be any 1 to 13 carbon atoms acyclic bridging compoundpreferably having 1- carbon atoms.

My compounds represented by Formula II and For.- mula III are producedby hydrogenation of an intermediate compound having the formulae:

wherein R R Y, p, m and n have the same significance as given in formulaIII.

The intermediate mixture of isomeric compounds of Formulae IV, V and VIis preferably formed by reacting a bridging compound with an alkylbenzene compound for a mixture of different alkyl benzene compounds inwhich benzene can be substituted for one of the alkyl benzene compounds.

Alternatively, but less economically, it is possible to first form adi-(phenyl)-alkylene bridge compound of the formula:

in which Y has the same significance as in Formulae I and IV formed bythe same bridging reactions as for Formula IV compounds, the Formula VIIcompound then being alkylated by usual alkylation methods to add 1 ormore alkyl groups of the formula R or R or a mixture of both to therings; thereby, forming a mixture of intermediate isomers of the formulaIV.

In a further alternate procedure, a mixture; of compounds of Formula VIImay be formed by bridging two phenyl groups with the alkylene bridginggroup and alkylating one or both rings with one or more lower alkylgroups in the presence of a suitable catalyst to promote both reactionsin the same reaction mixture.

The preferred bridging methods involve alkylation of two phenyl groupswith a single alkane such as acetylene; or a hydrocarbon diene; or anoxygen or dihalogen bear-- 5 ing aliphatic compound, at least one ofsaid phenyl groups being an alkylphenyl group of the formula as definedabove, employing an alkylating catalyst which may be an acid catalyst,usually a string mineral acid like sulfuric, phosphoric and/ orhydrofluoric acid; or a compound, e.g., like a boron halide or boronfluoride or their complexes, such as boron fluoride-phenylate, boronfluoride-etherate, boron fluoride dissolved in sulfuric acid, and otheracid alkylation and condensing agents with or without the Friedel-Craftstype catalysts. Where the bridging group carries two halogen atoms, aFriedel- Crafts type catalyst such as aluminum chloride may be usedalone.

When using sulfuric acid as a catalyst, the usual alkylating strength isabove about 80%, but generally below about 98%, above which sulfonationof the aromatic rings, or excessive condensation to polycyclic compoundsmay occur.

Particularly, such catalysts will be used to incorporate a bridginggroup derived from an aliphatic material comprising an aldehyde, aglycol, an alkylene oxide, an acetylene or alkyne, a diene, especially aconjugated diene, and a dihalo-alkane or the like. Acetylene itself andhigher alkyne compounds may be used as the bridging compound. Forpurposes of joining the alkyl benzene rings in the case of acetylene orother alkynes, the usual catalyst is mercuric sulfate, activated withstrong acid such as 85-98% sulfuric acid or a boron fluoridephosphoricacid complex. Alkylation reactions, as known in the art, generally areemployed at ambient temperatures and sometimes lower temperatures, suchas to i30 C. Certain catalysts such as hydrogen fluoride, known in theart, can operate at temperatures considerably below ambient temperaturessuch as 20 C. or lower.

Typically useful alkylphenyl producing groups are toluene, the ortho,meta or para xylenes and their mixtures, the trimethylbenzenes includingmesitylene, ethylbenzene, the diand tri-ethyl benzenes, the methylethylbenzenes, the dirnethylethyl benzenes, the diethylmethyl benzenes, themono-, di, and tri-propyl' benzenes, the n-butyl, secbutyl, tert-butylbenzenes, the isopropyl benzenes including cumene and pseudocumene,diisopropyl benzene, mono and di-amyl benzene, di-decyl benzene, withmixed alkyl groups including those with both normal and branched Cthrough C preferably C to C alkyl substituents, and the variouscombinations of alkyls within the limits of Formula IV.

When the bridging component is aldehyde, it can be formaldehyde,acetaldehyde, propionaldehyde, iso-butyraldehyde, decylaldehyde,do-decyl aldheyde and the like; when it is alkyne, it can be acetylene,methyl-acetylene, ethyl acetylene, and the like; when it is ahydrocarbon diene, it can be butadiene-1,3, a-llene, isoprene,piperylene, dimethyl butadiene and the higher dienes; when it is aglycol it can be ethylene glycol, propylene glycol-1,3, butyleneglycol-1,4, hexylene glycol-1,6, hexylene glycol- 1,2, decyleneglycol-1,10 and the like; when it is dihaloalkane, it is preferably adichloro, dibromo or chlorobromo compound within the limits of theFormula I or IV as given above; when it is alkylene oxide, it can beethylene oxide, propylene oxide, epichlorohydrin; or ketenes such asketene and the like.

In commercial practice an aromatic extract of a reformation oraromatization reaction (termed petroleum reformate) may be used in itsentirety, usually comprising the C to C aromatics which may also containup to 50% benzene, or select 0;, C or C fractions of such extract may beused singly. The C fraction comprising the three isomeric xylenes andethyl benzene sometimes contaminated with toluene and/or with some otherC aromatics may most economically be used in its entirety. This valuableC aromatic fraction may often first be distilled to separate the orthoxylene isomer leaving the mixed meta and para xylene isomers. The latterfraction can have its para xylene extracted for even more valuable uses,and the ortho and meta xylenes fractions recombined for use herein. Anyof these select xylene fractions or the entire C fraction, are useful inthe practice of this invention. Thus any petroleum refinery reformatehaving an economically recoverable quantity of aromatics may comprise auseful source material from which an aromatic extract may be obtainedand used as a source of the alkyl benzenes, either as a whole extract,or as select fractions thereof. A typical preferred C fraction maycomprise about 2% toluene, 10% p-xylene, 48% m-xylene, 19% o-xylene andabout 21% ethylbenzene.

In carrying out the bridging reaction, where predominantly the bicycliccompound is desired, the alkyl benzene is usually used in substantialexcess, :e.g., a 2 to 3 times molar excess in respect to the molarquantity of bridging group material employed, and where higherpolycyclic compounds are desirable such as the tricyclic and higherpolycyclic side reaction compounds (such as shown in Formulae II, III, Vand VI), a lower ratio down to about /2 to 3 moles of alkyl benzene permole of bridging compound is used. The catalyst may be usually addedthereto at room temperature, and if the bridging compound is difiicultto react, the temperature may be raised; if the bridging compound ishighly reactive, the temperature may be lowered, applying cooling orrefrigeration as needed, and the bridging group material is usuallyadded slowly, such as dropvvise over a several hour period, usuallyabout 4 to 12 hours, with continued agitation in order to avoidexcessive side reactions thereof, the conditions being modifieddepending on the activity of the reagents.

When the bridging reaction does not terminate by joining of only tworing groups, it is preferred to allow the reaction to convert only aportion, such as about /3 of the available alkyl benzene to the FormulaIV compound, before terminating the reaction. The reaction productFormula IV compounds are then recovered from the reaction mixture andthe excess unreacted compounds such as alkyl benzene are recycled to thereactor.

Olefinic compounds generally are to be avoided with :bridging reagentsexcept where both alkylation and alkylene bridging of two rings in thesame reaction in the presence of a selected catalyst for both reactionsis desired.

In the instance of reacting dihaloalkanes as the bridging groupcatalyzed with aluminum chloride, or an equivalent Friedel-Craftscatalyst, the alkyl benzene compound and the dihaloalkane are firstmixed, and usually is cooled to about 0 C. or less, and then thealuminum chloride can be added in any suitable manner, even rapidly.Such reactions are run with typical bridging compounds as ethylidenedichloride, hutylidene dichloride-1,4, hexylidene dichloride-1,6,isobutylidene dichloride-1,2, butylene bromochloride-l,4, propylenedibromide-1,3, ethylene dichloride-1,2, propylene dichloride- 2,2,isobutylene dibronrbide-LF: and the like.

After the position isomeric compounds of Formula IV are prepared, suchare freed of catalyst residues by decantation, filtration and/or waterwashing with or Without the aid of acid for Friedel-Crafts catalystsremoval, followed by an alkaline aqueous wash; or in the case of theacid catalyst by only water and/ or alkaline aqueous Wash. If theunreacted materials are not hydrogenated under the conditions employedfor such hydrogenation, then such unreacted materials need not beremoved; and the whole product may be hydrogenated; however, in mostinstances the unreacted materials are removed usually by distillationand the position isomeric compounds of Formula IV may be hydrogenated.Before hydrogenation, the Formula IV product may be further distilledfor greater purity to remove any side reaction product, such as thetricyclic and polycyclic compounds. The hydrogenation is usually carriedout in a diluent, e.g., a parafiin solvent in the presence of ahydrogenation catalyst'such as nickel or cobalt or other catalystcapable of hydrogenating aromatic compounds, etc. In the example anactive Raney nickel or Raney cobalt catalyst was preferred.

In order .that hydrogenation of the aromatic rings of Formula IVcompounds proceed at a reasonable rate, hydrogen is employed at noncritical elevated pressures, usually about 500 psi. to 5,000 psi. Tohydrogenate these aryl compounds, the temperature is raised noncritically above a minimum temperature, usually l- 200 C., or sometimeshigher, until hydrogenation commences. Each aryl ring usually has aminimum threshold hydrogenation temperature which must be exceeded andthis depends on the activity of the catalyst employed and on theposition of the alkyl substituents in the individual aryl rings. Thus byselective hydrogenation (control of catalyst activity, temperature andhydrogen pressure and which is sometimes influenced by the solventselected) one can hydrogenate only a single aromatic ring of thesebiarornatic ring compounds thus producing intermediate compounds offormulae:

wherein R and R Y, m and n have the same significance as in Formula I.

Accordingly, these partial hydrogenation position isomeric products ofFormulae VIII and IX are intermediates having more hydrogen thancompounds of Formula IV and less hydrogen than compounds of Formula Iand in a like manner compounds of Formulae V and VI can be partiallyhydrogenated.

Each of the partial hydrogenation products'of these formulae areintermediates per so, such as for further hydrogenation to form the jetfuels of Formula I, e.g., hydrogenation of phenyl methyl-cyclohexylmethane position isomeric mixture :to the cyclohexyl methylcyclohexylmethane position isomeric mixture.

The hydrogenated bicyclic compounds of Formula IV can contain a minorquantity, less than about 50%, of diphenyl bridged compound in thereaction mixture, for example, when a benzene and alkyl benzene mixtureis bridged, which does not need to be separated from the alkylphenylbridged compound of Formula IV but may economically be fullyhydrogenated therewith to a final hydrocarbon mixture, also useful for ajet fuel mixture.

As noted my products are a very complex mixture of position isomers evenin the simplest form, such as when produced with a methylene bridge, forexample, by condensation of alkyl-benzenes with methylene chloride orformaldehyde followed by hydrogenation. There are six position isomericdi-(methylcyclohexyl)-methanes which are present in a synthetic fuelprepared by hydrogenation of di-(itolyl) -methane (prepared for examplefrom toluene and formaldehyde, e.g., with sulfuric acid catalyst). Theyare di-(Z-methylcyclohexyl)-methane, di-('3-methylcyclohexyl)-methane,di-(4-methylcyclohexyl)-methane, (Z-methylcyclohexyl) (3-methylcyclohexyl)-methane, (Z-methylcyclohexyl) (4-methylcyclohexyl)- methane, and(3-methylcyclohexyl) (4-methylcyclohexyl) -methane.

Four other isomers formed by other methods of synthesis are:di-(l-methylcyclohexyl)-methane, (l-methylcyclohexyl)(Z-methylcyclohexyl)-methane, (l-methylcyclohexyl) (3-methylcyclohexyl)-methane and (l-methylcyclohexyl) (4-methylcyclohexyl)-methane.

Even though there are some perfectly symmetrical bis compounds possiblypresent, any one of these can be present only as a minor portion of eventhe simplest complex position isomer mixture.

For example, the di-.(methylcyclohexyl)-methanes have six isomers, butthe di-(dimethylcycohexyl) methanes have 144 possible position isomers,and 36 of these position isomers can be obtained by condensation offormaldehyde or methylene chloride with mixed xylenes, followed byhydrogenation.

A typical specific exemplification of the preparation of a mixture ofisomers of the present inventions is as follows: a mixture of ortho-,metaand para-ethyltoluenes obtained from petroleum or coal tar refiningis reacted with formaldehyde (e.g., using sulfuric acid catalyst at 30C.) to produce di-(methylethylcycohexyl)-methane containing all possibleposition isomers in varying amounts dependent on relative activities ofthe formaldehyde with the four different hydrogens of each of theethyltoluene isomers present in the starting materials of the synthesis.

It has been further found that the heat of combustion of isomericmixtures of such di-(dialkylcyclohexyl)- methanes is partially dependenton variations in ratios of the amounts of respective isomers present ina given product. Thus, the hydrogenated products derived from (a)reaction of a commercial xylene with formalin (37% formaldehyde) at 30C. followed by hydrogenation and from (b) reaction of the samecommercial xylene'with formalin (37% formaldehyde) at 60 C. containeddifferent amounts of the various isomers and showed -respectively 19,500gross B.t.u./lb. and 19,815 gross B.t.u./lb. for the heat of combustion.Similarly, the reaction of methylene chloride with xylene usinganhydrous aluminum chloride as catalyst, followed by hydrogenation gavea fuel of 19,605 Btu/lb. Thus the broad fractions of a given positionisomer mixture of di-(monoor di-alkylcyclohexyl)-methane from two ormore sources will dilfer in properties including the energy ofcombustion. The constancy of energy output of fuels from a givensynthesis is an important advantage of the fuels of the presentinvention, particularly for rocket fuels since target calculations arebased in part on the basis of known energy available from the fuelcharge. The operating variables of the methods of synthesis of the fuelsof the present invention are readily controlled to give a reproducibleproduct, hence reproducible heat of combustion.

By the reaction of formaldehyde with a mixture of the three xylenes andthree methylethylbenzenes, fol lowed by hydrogenation of thecondensation product, there was obtained a fuel containing a largenumber of isomeric (methylethylcyclohexyl) (dimethylcyohexyD- methanesand di-(methylethylcyclohexyl)-methanes, in addition to the manydi-1(dimethylcyclohexyl)-methane position isomers; the various xylyl andethylphenyl combinations as substituents for methane (in theformaldehyde condensation product) thus increased the number of isomersobtained in the final hydrogenated products of this invention incomparison to the hydrogenated xyleneformaldehyde reaction product alsoof this invention.

Thus di-(alkylphenyl)-methane can be made by reacting the alkyl benzenehydrocarbons or their mixtures with (a) formaldehyde (employing aFriedel-Crafts catalyst for example at 525 C.) and converted to fuels ofthe present invention by hydrogenation. Other catalysts and temperaturesmay be used to obtain a final hydrogenated 9 fuel of a difierentisomeric composition; i.e., different amounts of the various isomericdi-(alkylcyclohexyl)- methanes in comparison to these preparations.

The precursors (Formulae IV, V and VI compounds) were then hydrogenatedover Raney nickel catalyst (e.g., Girdlers G-49 catalyst) using about 8pts. by weight of methylcyclohexane as solvent for 1 to 4 pts. by weightof precursor. The hydrogenation was conducted at 100 to 200 C. under 65to 100 atmospheres of hydrogen pressure in a batch reactor withagitation for 2 to 8 hours. The methylcyclohexane solvent was removed bydistillation, the remainder being Water white to light yellow fuels ofthis invention.

In the examples, the terms used are defined:

(a) By the term gross heating value of a fuel is meant the total heatdeveloped on burning a fuel after the products are cooled back to theinitial temperature (usual practice 60 F.), assuming that all the waterproduced by combustion is condensed.

(b) By the term net heating value of a fuel is meant the total heatdeveloped on burning a fuel after the products are cooled hack to theinitial temperature (usual practice 60 F.), assuming the water ofcombustion is uncondensed.

INDEX OF EXAMPLES Materials Employed in Forming Hydrocarbon PrecursorCompounds Alkylhenzene Bridge Bridging compound (or alkylation) ExampleI Toluene Methyl--- Paraformaldehyde. Table I Cg thru Cu 1 o Do.

Toluene D0,, Cs aromati Do. Toluene Formaldehyde (37%). Toluene do1,1-dichloromethane. Crude xylenes do 0. p-Xylene do Paraformaldehyde.Crude xylenes do D0. Ethylbenzene do D0.

Diphenylmethane do Alkylated with ethylene. Cumene do Paraforrnaldehyde.Diphenylmethane do Alkylated with ethylene. Sec-butylbenzene doParaiormaldehyde. Toluene Ethyl Acetaldehyde. Cs ll llll' Cu 1 do Do.

Acetylene. Do

Acetylene, ethylene.

Acetylene.

Ethylene glycol.

do 1,2 dichloroethane.

PropyL... Propionaldehyde. do Do,

Xylenes do Do. do .d 1,2-dichloropropane. Toluene do 2,2dich1oropropane. Cs thru C11 do D0.

C aromatic do 1,2-pr0pyleneoxide. Toluene Butyl Butyraldehyde. Xylenesdo Do.

do Butadiene. Pentyl Piperylene. UndecyL Urlidgcylenic aldee. -do DecylDecamethylenedibromide-1,10.

1 Aromatic. 2 By reference.

EXAMPLE I (a) isomeric Mixture of Di-(Tolyl) -Methanes In this example,1660 grams (18.04 moles) of toluene, 96 grams (3 moles) methanol, 200grams of a mixture of 96.7% sulfuric acid (1.973 moles) containing 2.8grams (0.01 mole) ferrous sulfate heptahydrate were placed in a glassflask equipped with a stirrer, a reflux condenser, a thermometer, anopening for addition of reagents, and cooled in a water bath held at atemperature 18 to 21 C. To this mixture while stirring were added gramsparaformaldehyde (equivalent to 3 moles of anhydrous formaldehyde) overa period of 25 minutes. Stirring was continued for 60 minutes at about25 C. The water bath temperature was then raised to C. over a period of2.5 hours, with continuous stirring, and the mixture was then refluxedfor an additional hour. About 24 grams of formaldehyde vapors were lostthrough the condenser and the remainder of the formaldehyde (2.2 moles)from depolymerizatlion of the paraformaldehyde under condiions of thereaction, condensed with the toluene. The mixture was cooled, thehydrocarbon layer was separated from the acid, and washed with 2 litersof water followed by 2 liters of 1% sodium carbonate solution. The bydrocarbon was then heated to distill excess toluene at 760 mm. ofmercury pressure. The mixture of 'di- (tolyl)- methane position isomersdistilled over at 137 to 152 C. at 11 mm. mercury pressure; 354 grams ofthis isomeric mixture were obtained: iN =l.5700; D =0.996, M.P.=65 (3.;viscosity=0.65 poises at 25 C.

(b) Isomeric M ixiure of Di-(Methylcyclohexyl) -Metlzanes To 294.4 gramsof the di( tolyl)-methane position isomers obtained in (a) was added 800g. of methylcyclohexane, together with 58.9 g. of Rauey type nickelcatalyst (Girdler G-49 catalyst, Girdler Corp.) and the mixture wasplaced in a gallon autoclave unit equipped with a magnetic stirrer andpressured with 1000 p.s.i. of hydrogen at 22 C., and the autoclave washeated to C., the temperature being maintained over a pe riod of 4 hourswhile stirring. During this period three additional pressurings ofhydrogen were added to raise the hydrogen pressure each respective timefrom 400, 500 and 625 p.s.i. to 1000 p.s.i., indicating partialhydrogenationin stages. After the third addition, the temperature washeld at 120 to C. for 80 minutes. The pressure dropped to 975 p.s.i. andremained constant for the last 30 minutes. The autoclave was cooled, thecontents removed, filtered and the methylcyclohexane was separatedtherefrom by distillation. A quantitative yield of over 300 grams of aposition isomeric mixture of di- (methylcyclohexyl)-methanes wasobtained. H=l3.l5%, C=87.08%, N =1.4750; D =0.876; B.P.-=111-120 C. 7mm. Hg; melting point=below 70 C.; viscosity=1.4 poises at -25 0.; heatof combus'tion,=l9,787 B.t.u./lb. (gross), 18,555 B.t.u./lb. (net),136,070 B.t.u./ gallon (net).

Substituting-for the 1660 grams of toluene used in this example, 1910grams of o-xylene yields a mixture of the di-(o-xylyDa'nethane which arehydrogenated to the di- (-1,2-dimethylcyclohexyl)-methanes; :or 1910grams of mxylene yields the dii-(m-xylyD-methanes which are hydrogenatedto the di-(1,3- dirnethylcyclohexy1)-methanes; or 1910 grams of p-xyleneyields the di-(p-xylyl)-methanes which are hydrogenated to the di(1,4-dimethylcyc1o heXyD-methanes; or 1910 grams of mixtures of 2 or moreof o-xylene, m-xylene and p-xy-lene are likewise converted to themixture of d-i-(mixed xylyl)-methanes and hydrogenated to the :di-(mixeddimethylcyclohexyD-methanes; or 1910 grams of ethylbenzene is convertedto the di-(ethylphenyl)-methanes and hydrogenated to the di-(ethylcyclohexyl)-rnethanes; 1910 grams of a C aromatic fraction arealso converted to the di-(mixed C alkylphenyl)-methanes and hydrogenatedto the di-(mixed C di (di-alkylcyolohexyl)-methanes.

In this example, the quantity of alkylbenzene can be varied from 0.5mole of alkylbenzene per mole of formaldehyde, up to the 18 moles ofalkyl benzene or even higher per mole 'of formaldehyde. The excess ofthe alkylbenzene usually at least twice the molar requirement tends tokeep the system sufficiently dilute to minimize formation of tricycliccompounds and higher polycyclic; conversely use of lower proportions:down to 0.5 mole, produces substantial quantities of the higher cycliccom- TABLE I.MIXTURE OF POSITION ISOMERS-C01ltinued Alkylbenzene Di-(alkylph enyl) -meth anes Di-(alkylcyclohexyl)-methanester-amyl-p-toluene o-ethyI-mbutylbenzene. m-ethyl-n-butylbenzenep-ethyl-n-butylbonzene, o-ethyl-isobutylbenzene. m-ethyl-isobutylbenzene p-ethyl-lsobutylbenzene 1,3-dipropylbenzene- 1,4-dipropylbenzene-1,2-tliisopropylbenzen 1,3-diisopropylbenzene. 1,4-rliisopropylbenzene.1,2,3-triethylbenzene.-. 1,2,4-triethylbenzene. 1,3,4-triethy1benzene.

ter-amyl-m-toluene o-ethyltert-butylbenzene m-ethyl-tert-butylbenzenep-ethyl-tert-butylbenzene 2,3-dimethyl-n-butylbenzene- 2,a-dirnethyl-n-butylbenzene3,-dimethyl-n-butylbenzene 3,fi-dimethyl-n-butylbenzene2,3-dimethyl-sec-butylbenzen 2,4-dirnethyl-se c-butylbenzene-3,-dimethyl-sec-butylbenzene. 3,fi-dimethyl-sec-butylhenzene-..2,3-dimeth yl-tert-butylbenzene 2,4'dimethyl-tertbutylbenzene3,4-dimethyl-tert-butylbenzene. 3 ,5-dimethyl-tert-butylbenzene, 1,2-(1ipropylb enzene di-(o-ethyl-tert-butylphenyl)-methanes di-(ter-amyl-m-tolyl) -meth anes. di-(ter-amyl-o-tolyl)anethanes di- (o-ethyl-n-butylphenyl) -meth anes di- (m-eth yl-n-butylphenyl) -metl1anes.(li- (p-ethyl-n-hutylphenyl)-1neth anes.di-(o-ethyl-isobutylphenyD-rnethanes." dl (m-ethyl-isobutylphenyl)-methanes. di-(p-ethyl-isobutylphenyD-rnethanes--.

di-(ter-amyl-m-methyloyclohexyl) meth anes.di-(ter-tunyl-p-methyloyclohexyl)-1nethanes.di(o-ethyl-n-butylcyolohexyl)-methanes.di-(ru-ethyl-n-butylcyelohexyl)-Inethanes.di-(pethyl-n-butylcyclohexyl)-methanes.di-(o-ethyl-isobutyloyclohexyl)-methanes.di-(rn-ethyl-isobutylcyclohexyl)-methanes.rli-(p-ethyl-isobutylcyelohercyl)-methanes.di-(o-ethyl-tert-butylcyc]ohexyl)-Inethanes.

di- (In-e hyl-t ert-butylcycloh exyl) -Inethanes.di-(p-ethyl-tert-butylcyolchexyl)-methanes. di-(2,3-d imethyl-n-butyloyclohenD-nzethanes. di-(2,4-dimethyl-n-butylcyclohexyl)-n:ethanes.di-(3,4-dimethyl-n-butyloy clohexyl)melhanes.d1-(3,5-dimethyl-n-butylcyclohexyl)nethanes.di-(2,3-clirnethyl-sec-butylcyclohexyl)-n:ethanes.di-(2,4-dimethyl-sec-butylcyolohexyl)anemones.di-(3,4-dimethyhsec-butylcyclohexylyme1hones.di-(3,5-din:ethyl-sec-butylcyclohexyl)-methenes.

di-(2,3-di1nethyl-tert-butylcyclohexyl) anet hones.di-(2,4-dimethyl-tert-butylcyclchexylyroeth anc-s. di-,-dimethyl-tert-butylcyc'lohexyD-methanes.(ii-(3,4-dimethyl-tert-butylcy c-lohe; yD-lretl. ones.

(ii-(1,2-diprcpylcyclohexyl) methancs.(ii-(1,S-dipropylcyclohexyl)-methanes.di-(l,d-dipropylcyolohexyl)-Inelher es. di-(1,2-diisopropylcyclohexyl)inethanes.di-(l,B-diisopropylcyclohexyl)-meth anes.di-(1,4-diisopropylcyclohexyl)nethanes.di-(1,2,3-triethylcyclohexyl)-meth anes.di-(1,2,4-triethylcyolohexyl)-meth anes.(ii-(1,BA-triethylcyclohexyl)-meth anes.di-(n-hexylcyclohexyl)-methones.

n-hexylbenzene 2-isohexylbenzene 3-isohexylbenzenetert-hexylbenzene C12aromatic fraction di-(n-hexylphenyl)-rnethanesdi-(Z-isohexylphenyl)-1nethanes di-(3-isohexylphenyl) -Ineth anesdi-(tert-hexylphenyl)-methanest di-(Oa alkylphenylymethanes di-(2-isohexyleyclohexyl)-rnethanes. di-(3-isohexylcyclohexyl)-methanes.di-(tert-hexylcyclohexyD-meth anes. di-(Cfi alkyloyclohexyl) -methanes.

B Cs alkyl groups include three methyl-, methyland ethyl-, propylandisopropyl-groups.

C4 alkyls groups include two methyl-, butyl-groups.

and one ethy1-, two ethyl-, a methyland propyl-, a methyland isopropyl-,n-butyl-, isobutyl-, tert- 05 alkyl groups include two ethyland onemethyl, one ethyland one propy1-, one ethyland one isopropy1-, onemethyland one n-buty1 one methyl-, and one isobuty1-, one methyland onesec-butyl-, one methyland one tert-butyl-, one n-pentyl-, the severalbranched and unbranched primary pentyl-, the several isopentyls-, twosec-pentyls, tert-pentyl-groups.

* Cselkyl groups include three ethyl-, methyland ethyland propyl-,methyland ethyland isopropyl-, two propyl-,

two isopropyl-, two methyland one n-butyl-, two methyland onesec-butyl-, two methyland one tert-butyl-, one ethyland one n-butyl-,one ethyland one sec-holy one ethyland one tert-butyl-, methyland amyl-,the methyland seo-amyl, the methyland tertamyl-, the seven branched andunhranched pri-hexyh, the six sec-hexyls-, the two isohexyls-, and threetert-hexyl-groups.

In Example I and in the examples of Table I, the alkylbenzenes employedfor illustrative purposes include alkyl substituted benzenes for which:(a) the total carbon count of the alkyl group or groups on the benzeneis 1 to 6, it being understood that the 7 to 13 carbon countalkylbenzenes likewise can be employed; (b) alkylbenzones with twodiiferent alkyl groups are substituted on the benzene, it beingunderstood that alkylbenzenes with three different alkyl groupssubstituted on the benzene likewise can be employed; (0) position isomermixtures are prepared from a single alkylbenzene, it being understoodthat the mixtures of different alkylbenzenes or one or morealkylbenzenes and benzene can likewise be employed to produce a largernumber of position isomer precursor compounds and their hydrogenatedproducts in which R and R of Formulae I and IV are different alkylsubstituents.

While Table I and the tables hereinafter show examples of the positionisomers according to Formula IV and the hydrogenated products accordingto Formula I, the tables are understood to also exemplify the partialhydrogenated products according to Formulae VIII and IX; and it isfurther understood that there are exemplified herein the higher positionisomers (prepared by increasing the ratio of bridging compound to thealkyl benzene compound in the reaction) according to Formulae V and VI,and the hydrogenated products thereof according to Formulae II and III,and also the partial hydrogenated products of Formulae V and VI andcombinations of these.

EXAMPLE II (a) Mixture of Di-(TolyD-Meflzanes The procedure of Example Iwas repeated using 3 moles of paraformaldehyde in the same apparatus.The catalyst was 1.5 moles of 78% sulfuric acid and the paraformaldehydewas added in small increments over 3 drate.

hours with the temperature being raised from 20 C. to 59 C. during thecourse of the addition and held at an average temperature of 48 C. for 1hour. The product di-(tolyD-methane distilled at 180/ 10 mm. Hg pressureto give less than 5 grams of di-(tolyD-met'hanes. This exampleillustrates the approximate lower useful limit of acid concentration ofthe reaction.

EXAMPLE III (a) Mixture of Di-(XylyD-Methanes Example I was repeatedusing instead of toluene, a commercial synthetic Xylene mixture with thefollowing analysis:

0.5% toluene, 20.0% ethylbenzene, 20.0% p-xylene, 42% m-xylene, 16%o-Xylene, 1.5% higher boiling (e.g., ethyltoiuene). Eighteen moles (1910grams) of this xylene mixture was reacted with 4 moles paraformaldehyde,3 moles methanol and 4 moles 96.7% sulfuric acid containing 0.01 mole offerrous sulfate heptahy- The time of addition of the paraformalldehydewas 25 minutes and the temperature during addition was gradually raisedfrom 29 to 59 C. The temperature was then raised slowly to about 70 C.and maintained while stirring for an hour. It was estimated that theloss of formaldehyde was 29 g. or 0.97 mole. The product after waterWashing and caustic washing as in EX- ample I was distilled to yield416.3 g. of product distilling at 152 to 167 C./2 mm. Hg and 200 gramsresidue, a higher condensation product of di-(xylyD-methane with xyleneand formaldehyde, apparently di-(xylyl)-methyl'- xylene having thestructure of Formula VI R and R =CH Y=CH P=2, m=2 and n=3. The above416.3 grams was a mixture containing the position isomers ofdi-(ethylphenyl)-methane, di-(xylyD-methane, and (XylyD-(ethylhenyI)methane represents 1.86 moles of product. This mixture had an 'N=1.5663; D =0.978; M.P.=-40 C.; viscosity=27 poises at (b) MixedDi-(Dimethylcyclohexyl)-Methanes and Higher Homologues One mole of thedi-(xylyD-methane product of Example *III (a) (224 g.) was hydrogenatedaccording to the procedure of Example I using 38.8 g. Raney nickelcatalyst and 800 g. methylcyclohexane as solvent. The conditions ofhydrogenation were: 130-134 C. for 70 minutes at 350 to 750 p.s.i.hydrogen pressure. The water white product was a mixture of threecomponents, namely di-(dimethylcyolohexyl)-methane,di-(ethylcyclohexyD-methane, and(dimethylcyclohexyl)-(ethylcyclohexy1)-methane and each componentcomprised numerous position isomers, obtained in about 90% yield and itsproperties were: B.P.=120130 C./1 mm. Hg; M.P.'=below -70 C; N =1.476O;D =0.876; viscosity=5 poises at 25 C. The elemental analysis was 88.65%carbon and 13.39% hydrogen. The energy of combustion was 19,760B.t.u./lb. (gross), 18,513 B.t.u./'lb. (net), 137,420 B.t.u./ gallon(net). Substitution of sulfuric acid-phosphorous pentoxide combination(0.33 mole P per mole of formaldehyde), the concentration of thesulfuric acid does not change during the reaction since the water ofcondensation converts the 7 P 0 co-phosphoric acid:

When operating in this manner, the productivity of the sulfuric acidcatalyst is much higher. Also substitution of hydrofluoric acid for thesulfuric acid in the above procedure produces high yields ofdi-(alkylaryl)-methanes which is hydrogenated to a fuel having an energof combustion greater than 135,000 B.t.u./ gallon.

EXAMPLE IV (a) Mixtures of Di-(T0lyl)-Methanes In this example toluenewas reacted with formalin (37% formaldehyde) instead of paraformaldehydeused in Example I. 820 grams (7.5 moles) of 89.5 sulfuric acidcontaining 2.8 g. (0.01 mole) ferrous sulfate heptahydrate was addeddropwise to a mixture of 1842 grams (20 moles) toluene, 203 grams (2.5moles) 37% formalin and 40 grams (1.25 moles) methanol while stirring.The temperature of reaction Was maintained in the range of 1 8 to 29 C.by a cold water bath. The time of the acid addition was 77 minutes. Themixture turned dark purple during the acid addition. Stirring wascontinued for 1 hour at 192l C. after the addition of the acid wascompleted. The mixture was then diluted with 1 liter water and wellshaken, the upper hydrocarbon layer was separated, washed and distilledfrom a Claisen flask to separate the unreacted toluene and 179 g.(0.91-lmole) of di-(tolyl)-methane was obtained distilling at 149 to 184C./ 10 mm. Hg pressure with a residue of 95 g. having a refractive indexof Ni of 1.601. The residue is isomers of di-(tolylmethyD-toluene (0.32mole). Thus it is estimated that 1.55 moles HCHO reacted, 0.95 mole HCHOescaped through the condenser or was washed out of the final reactionmixture. The yield of di-(tolyl)- methane was 59% based on formaldehydereacted, and the di-(tolyl)-methane comprised 66% of thearyl-hydrocarbon reaction products. The characteristics measured on thisdi-(tolyl)-methane product were: N =1.56l8; D =0.979; F.P.=below -65 C.;viscosity=5 poises at -50 C.

(b) Mixtures of Di-(Methylcyclohexyl)Methanes This material whenhydrogenated over Raney nickel according to the procedure of Example Igave a fuel having over 136,000 B.t.u./ gallon. When xylene (20 moles)is substituted for toluene in the above example, the final hydrogenatedfuel comprises mixed isomers of di- (dimethylcycle-hexyl)-methane. Whentrimethylbenzene (20 moles) is substituted for toluene in the aboveexample, the final fuel comprises isomers ofdi-(trimethylcyclohexyl)-methane.

EXAMPLE V (a) Mixtures of Di-(TolyD-idethanes One mole of1,1-dichloromethane grams) was weighed into a 4-liter glass vesselequipped with condenser, agitator, thermometer, an opening for additionof components, the vessel being immersed in an ice/water bath. To it wasadded six moles (552 grams) of dry toluene while stirring; when thetemperature of the very mildly stirring mixture had fallen to 5 C. aboutone-half mole (65 g.) of powdered aluminum chloride (anhydrous) wasadded over a period of 15 minutes. HCl fumes were evolved slowly andafter addition of the AlCl was completed the stirrer was stopped and theflask was allowed to stand 24 hours, the ice in the cooling bath beingallowed to melt, the temperature rising gradu ally to room temperature.The reaction mixture was poured into 700 grams of ice and 30 m1. conc.hydrochloric acid, the whole heated to near reflux, then cooled to 50 C.The hydrocarbon layer Was separated, washed with an equal volume of 1%hydrochloric acid solution, and heated to distill oflf the unreactedtoluene along with small amounts of water; 118 g. of a fraction,di-(tolyl)- methanes, distilling at 135-l50 C./2'3 mm. Hg (11 1.5680)(and leaving a tarry residue of about 30 grams) was obtained ing atl35-145 C. (30 g.).

(b) Mixtures of Di-(Methylcyclohexyl)-Methanes Of thisdi(-tolyl)-methane, grams was hydrogenated as in Example I to yielddi-(methylcyclohexyl)- methane; B.P.=-l20/ 7 mm. Hg, in substantiallyquantitative yield.

Alternatively, following the procedure of Example V other Priedel-Craftscatalysts may be substituted for the aluminum chloride. Thus BF VCl BeCland the like produce di-(tolyl)-methane from toluene and methylenechloride. The position isomeric composition of the final hydrogenatedfuel is different for each catalyst, but in every case the energy valueis greater than 135,000 B.t.u./ gallon.

EXAMPLE V1 (0) Mixed Di- (Xylyl) -Methanes In Example VI the procedureof Example V was repeated using currently produced commercial xyleneshaving the following analysis: 2% toluene, 10% p-xylene, 48% rn-xylene,19% oylene, 21% ethylbenzene.

(b) Mixed Di-(Dimethylcyclohexyl)-Methanes The final hydrogenatedproduct was similar but not identical to that obtained in Example V,having slightly lower density and slightly higher combustion energy.

EXAMPLE VII (42) Mixtures of Di-(Xylyl)-Methanes In this example, theprocedure of Example III was repeated using a xylene of about 90%p-xylene content, and 10% oand m-xylene combined. The tendency to formresins with formaldehyde resulted in lower yields of the desireddi-(xylyl)-methane position isomers product when the same reactionconditions were employed.

(b) Mixtures of Di-(Dimethylcyclohexyl)-Methanes This product of (a) washydrogenated to produce a fuel of net heat of combustion greater than135,000 B.t.u./ gallon.

following a xylene fraction distill- 1 Z EXAMPLE VII-A a) Mixture ofDi-(Xylyl) -Methflnes The procedure of Example III was employed to reactcommercial xylenes (of same composition as set forth in Example V1) withformaldehyde. Forty moles (4247 grams) of the xylenes were placed in thereaction vessel (used in Example I) together with moles methanol (320g.), 0.02 mole ferrous sulfate heptahydrate (5.6 g), and 10 moles 96.1%sulfuric acid (1021 g). Ten moles paraformaldehyde (300 g.) were addedover a period of 3 hours and fifty minutes to the reaction vessel whilestirring and maintaining at 4045 C. After 45 minutes additionalstirring, 2 more moles of 96.1% sulfuric acid (204 g.) were added over aperiod of 1.5 hours and heat was applied during this addition so thatthe temperature of the reaction mixture gradually increased to 52 C.when the acid was all added. The acid layer was removed, the upper layerwas washed once with 1 liter of water, once with 1 liter of 3% Na COsolution, and three times with three successive liters of water.Distillation of the hydrocarbon products at 745/rnrn. Hg gave thefollowing fractions boiling above 200 C.:

0/745 mm. Hg

Yield (g.)

Fractions 200-300 300-319 3 19-326 326-340 340-380 380-400 400 ResidueFractions 2-6 weighing 1822.9 grams distilling from 300 to 400 C. is themixture of isomeric di-(xyly1)- methane precursors of this invention.

(b) Mixture of Dz-(Dimethylcyclohexyl)-Methanes Hydrogenation of 673grams of fraction 3 above was carried out using the procedure andautoclave of Example L Pentme solvent (1800 ml.) was used instead ofmethylcyclohexane solvent, and 101 grams of Girdlers nickel catalystG-49A was used. After maintaining the autoclave at 155 to 195 C. under500 to 800 p.s.i. hydrogen pressure for 16 hours, no further hydrogenwas absorbed. The contents of the autoclave were filtered, the pentaneremoved by distillation, and 662 grams ofdi-(dimethylcyclohexyl)-methanes was obtained having the followingproperties:

The product was redistilled to yield a principal fraction having thefollowing properties: B.P.=295302 C./ 745 mm. Hg; n =1.4759; D ='O.865;M.P.:below --50 C.; viscosity= 0.5 poise at 30 C.; and the gross heat ofcombustion was 19,615 B.t.u./lb.

(c) Mixtures of Di-(c -Alkylphenyl)-Mefluznes and Hydrogenated ProductsT hereof B.t.u/ gallon.

EXAMPLE VIII ((1) l'i Iixlures of Di-(Ethylphenyl)-Methanes A glassflask equipped with a stirrer, a reflux condenser, a thermometer and anopening for addition of reagents was warmed in a water bath at anaverage temperature of 50 C. To the reaction vessel was added 1910 grams(18 moles) of ethylbenzene, 406 grams (4 moles) of 96.9% sulfuric acid,5.3 grams (0.02 mole) of ferrous sulfate heptahydrate, 64 grams (2moles) of methanol and grams (4 moles) of paraformaldehyde was added insmall increments over a 2 hour period; the temperature of the reactantsaveraged 51 C. Stirring was continued at 50 C. for another half hour.During the reaction, the color changed to dark purple. The hydrocarbonlayer was decanted, washed with a liter of water followed by a liter of3% aqueous solution of sodium carbonates and then finally washed with 1liter of water. The unreacted material was distilled off and the productdistilled as follows:

Fractions B.P., 0. NW Yield (g.)

1 mm. Hg

1 Residue.

Fraction 1 was an amber fluid, fraction 2 was a clear fluid and fraction3 was a dark red viscous fluid.

(b) Mixtures of Di-(Ethylcyclohexyl)-Methanes EXAMPLE VIII-A (a).Mixtures of Di-(Ethylphenyl)-Methanes To a pressure vessel withagitator and cooling jacket is added 168 grams (1 mole) ofdiphenylmethane, 102 grams (1 mole) of 97% sulfuric acid, 13.5 grams ofgaseous boron fluoride and the pressure vessel is attached to a 100 psi.ethylene line and pressured therewith. The reactants are rapidlyagitated and the reaction temperature is maintained at 300 C. After thereaction mixture has taken up 56 grams (2 moles) of ethylene, theethylene is shut toil and the vessel vented and the reactants removed.The hydrocarbon layer is sepae rated from the acid layer and poured ontoa kilogram of ice, followed by Washing with 1 liter of 3% aqueous sodiumcarbonate solution and 1 liter of water. Any unreacted diphenyl-methaneis distilled off and the product is a mixture of position isomers ofdi-(ethylphenyl)- methane (or other di-(ethylphenyl)-alkanes) containingsmall amounts of mono-tri- (and higher) ethyl-di- (phenyl) -methanes.

(b) Mixtures of Di-(Ethylcyclohexyl)-Merhanes (c) Mixtures ofDi-(Alkylcyclohexyl)-Alkanes Prepared From Benzene or Alkylbenzene, aCompound Providing the Y Bridge and an Olefin In place of the 1 mole ofdiphenyl-methane employed in Example (a) above, 2 moles of benzene and 1mole of a bridging compound such as a hydrocarbon diene, e.g.,butadiene, i soprene, piperylene and the like homologues up to andincluding C homologues, or mixtures of these (see Examples XIV-C, XXVIand XXVI!) may be added concurrently or alternately with 1 to 3 19 molesof olefin, e.g., ethylene, propylene, butylene, isobutylene and the likehomologues up to and including C homologues, or mixtures of theseolefins and with the aid of a suitable alkylating catalyst, e.g.,sulfuric acid and boron fluoride as set forth in (a) hereof, andconverted to the mixture of position isomers of the correspondingdi-(alkylphenyD-alkane (Formula IV) which is subsequently hydrogenatedas set forth in (b) above to the mixture of position isomers of thecorresponding di-(alkylcyclohexyl) -alkanes (Formula I) or the partiallyhydrogenated compounds corresponding to Formulae VIII or IX herein.

When it is desired to produce di-(alkylcycohexyl) -alkanes or di-(trialkylcyclohexyl) -alkanes with the same or different alkylsubstituents on the cyclohexyl radicals then one can employ benzenetogether with two or more olefins and a compound supplying the Ybridging radical; or one may employ one or more C to C -alkylbenzenestogether with one or more olefins and @a compound supplying the Ybridge; and these materials are converted in a like manner as set forthin this example or in the other examples herein with the aid of analkylation catalyst to the position isomers corresponding to Formula IVherein and wit subsequent hydrogenation position isomers correspondingto Formula I or VIII or IX herein (refer to Example XIV-A) EXAMPLE IX(a) Mixtures of Di-(Isopropylphenyl)-Methanes A glass flask equippedwith a stirrer, a reflux condenser, a thermometer and an opening foraddition of reagents was heated in a water bath at a temperature 45 to50 C. To this reaction flask was added 480 g. (4 moles) of cumene, 100g. (1 mole) 96.9% sulfuric acid, 32 g. (1 mole) of methanol, 1.1 g.(0.005 mole) of ferrous sulfate heptahydrate and over a 2 hour periodwas added in small increments 30 g. (1 mole) of paraformaldehyde. Thehydrocarbon layer was separated, washed with 1 liter of 3% sodiumcarbonate aqueous solution followed by 1 liter water. The unreactedcumene was removed by dis tillation. The product was distilled asfollows:

1 Distillates had slight greenish tinge.

(b) Mixtures of Di-(lsopropylcyclohexyl) -Methanes Fractions 1 through 4were combined for hydrogenation (and if desired the residue could alsobe included). The hydrogenation was carried out as in Example I and thedi-r(isopropylcyclohexyl) -methane position isomer mixture had a netfuel value greater than 135,000 B.t.uJgallon.

EXAMPLE '-lX-A (a) Mixtures of Di-(Isopropylphenyl)-Methanes To a glassvessel equipped with a stirrer in a water bath at 20 C. is added 168grams (1 mole) of diphenyl methane, 102 grams (1 mole) of 97% sulfuricacid and over a period of 4 hours propylene is bubbled into the rapidlyagitated reactants so that 105 grams (2.5 moles) of propylene arereacted. The hydrocarbon layer is separated from the acid layer andwashed with 1 liter of water, 1 liter of 3% aqueous sodium carbonate andagain with 1 liter of water and any unreacted diphenyhnethane is removedby distillation. The resulting product is primarily di-(isopropylphenyl)-methane with a small amount of (isopropylphenyl)(phenyD-methane and (diisopropylphenyl) (isopropylphenyl)methaneposition isomers.

these same are converted to a v propyl-phenyl -methane The preparationof these position isomers is conducted similarly as described in (a) ofthis example, only the reaction temperature is maintained at 2 C. withthe of an ice bath and propylene is bubbled in over a 6-hour period oruntil the react-ants take up 172 grams (4.1 moles) of propylene, and theacid layer is decanted and the hydrocarbon layer washed yielding mainlydi-(isopropylphenyl) -methane. In Examples IX-A '(a) or (b) a half moleof boron fluoride can be :added to speed up the reaction and the ratioof position isomers.

(c) Mixtures of (Isopropylphe-nyl)-(Phenyl)-Meth ane Alternately inExample IX-A 46 grams (1.1 moles) of propylene can be combined, chieflyforming the (isopropylphenyl (phenyl) -meth'ane.

(d) Mixtures of Di-(Isopropylcycloxhexyl)-Methane (e) Mixtures of Di-(Diis0pr0pyl-Cyclohexyl) -Methane This example is conducted similarly toExample lX-A (d) above except that 20 grams of principally d-i-(diisoisemployed and the product from hydrogenation isdi-(diisopropyl-cyclohexyl)-methane which is useful as a fuel having anet energy of combustion greater than 135,000 Btu/gallon.

(f) Mixtures of (Isopropylcyclohexyl)*(CyclohexyD- Methane 1 Thisexample is conducted similarly to Example lX-A (d) except that 20 gramsof (isopropylphenyl)-(phenyl)- methane is employed and the product fromhydrogenation is (isopropylcyclohexyl) (cyclohexyl)-methane which is auseful fuel having a net energy of combustion greater than 135,000B.t.u/ gallon.

In place of the 1, 2 and 4 moles of propylene in Examples IX-A (c), (a)and (b) alpha-isoolefins can be employed such as isobutylene,isopentylene, isohexylene, diisopropylene, tri-propylene, diisobutylene,triisobutylene and the like or other alphaolefins such as ethylene,butene-l, pentene-l, hexene-l and the like and when employing thesealpha-olefins, it is sometimes necessary to increase the sulfuric acidcatalyst efficiency by adding boron fluoride (e.g. 0.5 mole boronfluoride per 1 mole of concentrated sulfuric acid see Example .VIll-A)In place of the 1 mole of diphenyl-methane may be added 1 mole of one ormore of the diphenyl derivative of ethane, propane, butanes, isobutane,the pentanes, e hexanes or any compound of Formula VII, i.e.

in which Y is an alkane bridge radical having 1 to 13 car bon atoms.These various position isomers produced by alkylating compounds of thetype of Formula VII produce compounds of the type of Formula IV whichwhen hydrogenated (as per Example lX-A (d produces position isomer fuelsof Formula I according to this invention.

EXAMPLE X (a) Mixture of Di-(Sec-Butylphenyl)-Methanes A glass flaskequipped with a stirrer, a reflux condenser,

a thermometer and an opening for addition of reagents was heated in awater bath at a temperature of 50 C. To the reaction vessel was added805 grams (6 moles) of sec-butylbenzene, 152 grams (1.5 moles) of 96.9%

22 aldehyde (B.P. 21 C.) vapors were lost through the condenser.Stirring was continued for 85 minutes during which time the temperaturedecreased to 3 C. indicating most of the reaction was over. The darkbrown mixture sulfuric acid, 24 grams (0.75 mole) of methanol, 1.1 wasallowed to warm to 25 C. The acid layer did not grams (0.005 mole) offerrous sulfate heptahydrate and readily separate and soda ash (400 g.)was added graduover a period of 1.5 hours was added in small incrementsally with stirring to neutralize the acid. The solution 45 grams (1.5moles) of paraformaldehyde. During the warmed up and some unreactedacetaldehyde distilled out reaction the average temperature of thereactants was 55 of the mixture during this process. It was calculatedfrom C. After 0.5 hour continued stirring, the hydrocarbon productweights that a total of 2.24 moles of the added product was decantedfrom the acid layer and washed with aldehyde was lost by vaporization.The aqueous layer 1 liter of water followed by 1 liter of 3% aqueoussodium was removed, the hydrocarbon layer was water-washed carbonatesand finally with 1 liter of water, and the unwith 1500 ml. water and thetoluene distilled off. The reacted-materials removed by distillation.toluene-free product was distilled at atmospheric pressure The productwas distilled as follows: and the fractions collected were as follows:

. O Fractions B.P., O./ N n Yield (g.) Fractwns B.P., 0. N 3 Yeld g.

745mm.H g l mmm'Hg 30.1350 1.5211 7.9 335533 t-ggg; a

1 4!05 solid 4311 315-325 1. 5628 21.

1 Residue. sag-380 (1 .)5539 Fractions 1 to 4 were liquids some solidmaterial separated from fraction 5 and fraction 6 solidified with amelting point about 50 C.

( 1)) Mixed Di- (Sec-Butylcyclohexyl) -Mezhanes and Higher FractionsFractions 2 to 5 were combined and hydrogenated according to theprocedure of Example I to yield a position isomer mixture which had anet fuel value greater than 135,000 B.t.u./gallon.

EXAMPLE XI (a) Mixtures of 1,1-Di-(T 0lyl)-Ethanes In a 4-liter glassreaction vessel identical with that of Example I were placed 1658 g. (18moles) of toluene and 406 g. (4 moles) of 96.7% sulfuric acid. The flaskwas cooled in an ice bath to 5 C. and while vigorously agitating thetoluene-acid mixture, acetaldehyde (4 moles) was added dropwise over aperiod of minutes. The temperature rose to a masdmum of 15 C. during theaddition of the aldehyde, the initially colorless mixture graduallyturned orange, red and dark brown successively. Some 1 Resinous residue.2 Dark solid.

Fractions 1 to 10 combined weighed 316.5 grams which distilled at255-680" C., with the main portion distilling from 298-325 C. This totaldistillate had the following properties: D =0.976; N =1.5600;-M.P.=below C.; viscosity=5 poises at -25 C.

(b) Mixtures of 1,1-Di-(Methylcyclohexyl)-Ethane Fractions 1 through 10were combined and hydrogenated by the procedure of Example I to yieldthe position isomers of 1,l-di-(methylcyclohexyl)ethane having a densityof D =0.891 and N =1.4800 and a heat of combustion of over 136,000B.t.u./ gallon.

Following the procedure of Example XI, but for the 18 moles of toluenesubstituting 18 moles (a substantial excess over that required forstoichiometric reaction with the acetaldehyde) of other alkylbenzenes,corresponding 1,1-di-(alkylphenyl)-ethane position insomer mixtures areproduced which, when hydrogenated, give the corresponding1,1-di-(alkylcyclohexyl)-ethane position isomers as set forth in TableII.

TABLE II.VIIXTURE OF POSITION ISOIVIERS 1,1-di-(alky1cyclohexyl)-ethanesNo Alkylbenzene 1,1-di-(a1ky1phenyl)ethanes ethylbenzenedi-(ethylphenyD-ethanes di-(ethylcyelohexyD-ethanes. o-xylene.di-(o-xylyl) -eth anes di- (1,2-dimethy1cyclohexyl) -ethanes. m-xylenedi-(m-xylyl)-ethanes di-(1,3-dimethylcyclohexyl)-ethanes. p-xylene"di-(p-xylyD-ethanes di-(l,-dimethylcyclohexyl)-ethanes.

Cs aromatic .1 acnon o-ethyltoluene p-ethyltoluenel,2,3-trimethylbenzene 1,2,4-trirnethy]henzene 1,3,5-trimethylbenzene.n-propylbenzene isopropylbenzene O9 aromatic fraction. o-n-propyltoluenem-n-propyltoluene p-n-propyltoluene mixed isomers of propyltolueneo-isopropyltolucne m-isopropyltoluene p-isopropyitoluene1,2-diethylbenzene 1,3-diethylbenzene. L-diethylbenzene1,2-dimethyl-3-ethylbenzene. 1,2-dimeth, -ethylbenzene 1,3-dimethy-2-ethylbenzene 1,3 methyl--ethylbenzene irnethyl-fi-ethylbenzene l ,31,4-dirnethyl-Q-ethylbenzene. n-butylbenzene See footnotes at end oftable.

(ii-(C; alkylphenyD-ethanes di-(o-ethyltolyl)-ethanesdi-(rn-ethyltolyD-ethanes.

di-(n-propylphenyl)-etl1anesdi-(isopropylphenyl)-ethanes (Ii-(03alkylphenyD-ethanesdi-(o-n-propyltolyl) -eth anes.di-(rn-n-propyltolyl)ethanes. di-(p-n-propyltolyl)-ethanes di-(o-, 1n-,and p-propyltolyD-ethanesdi-(o-isopropyltolyl) -eth anesdi-(lA-diethylphenyl)-ethan es di-(1,2-din1ethyl-3-ethylphenyl)-ethar1esdi-(l,Z-dirnethyl-4-ctl1ylphenyl)-ethanesdi-(1,3-din:ethyLZ-ethylphenyl)-ethanesdi-(1,3-dimethyl-4-ethylphenyl)-ethanes(ii-(1,3-dimethy1-5-ethylphenyD-eth anes.di-(1,4-dimethyI-Q-ethylphenyD-ethanes. di-(nbutylphenyl)-ethanes(ll-(02 alkylcyclohexyl)-ethanes. di-(o-ethyl-methylcyclohexyl)-eth ancs. di-(m-ethyl-methylcyclohexyl)-ethanes.di-(p-ethyl-methylcyclohexyl)-ethanes.di-(l,2,3-trimethylcyclohexyl)-ethanes.di-(l,2A-trimethylcyclohexyl)-ethanes.di-(l,3,5-trimcthylcyclohexyl)-ethanes. di-(n-propylcyclohexyl)-ethanes.di-(isopropylcyclohexyl)-ethanes.

di-(C; alkylcyclohexyl)-ethanes.(li-(o-n-propylmethylcyclohexyl)-ethanes.di-(m-n-propylmethylcyclohezyl)-etha11es.di-(p-n-propylmethylcyclohexyl)-eth anes. di-(o-, 1n-, andp-propylmethylcyclohexyl)ethmes. di-(o-isopropylmethyleycloheiql)-ethanes. dl-(rn-isopropylmethylcyclohexyl)-ethancs.di-(p-isopropy]methylcyclohexyl)-ethancs.di-(1,2-diethylcyclohexyl)-ethanes. di-(1,3-dietl1ylcycloheryl)-ethanes.di-(l,-diethylcyoloheryl}-ethanes.di-(1,2-di1nethyl-3-ethylcyclohexyD-eth anes.di-(l,2-(1iruethyll-ethylcyclohoxyl)-ethanes.di-(l,3-dimethyI-Z-ethylcyclohexyl)-ethanes.di-(1,3-dimethyl-4-ethylcyclohexyD-eth anes.di-(LS-dimethyl-5-ethylcyclohexyD-ethanes.di-(1,4-dimethyl-Q-ethylcyclohewD-ethanes.di-(n-butylcyclohexyl)-etl1anes.

TABLE II.MIXTURE OF POSITION ISOMERS-Continued Alkylbeuzene1,l-di--(alkylphenyD-ethanes 1,1-(dl-alkylcyclohexyl)-ethanesdi-(seo-butyloyolohexyl)-ethanes.

sec-butylbenzene di-(tert-butylcyelohexyl)-othanes.

tert-butylbenzene C aromatic fract1on,

1,2-diethyl-3-methylbenzene 1,2-diethyl-4-methylbenzene.

hylbenzene l,3-diethyl-5methylbenzene. 1,4-diethyl-2n1ethylbcnzene.o-meth yl-n-butylhenzene m-mothyl-n-hu tylbenzene. p-m ethyl-lsobutylbeuzene o-methyl-lsobutylbenzene mmethyl-lsobutylbenzenep-methyl-isobutylbenzene o-methyl-tert-butylbenzenemrnethyl-tert-butylbenzenc p-m ethyl-tert-butylbenzeneo-othyLn-propylbenzene m-ethyl-n-propylbenzenepethyl-upropylbenzene. o-ethyl-isopropylbenzenem-ethyl-lsopropylben zenen-ethyl-isopropylbenzene 1,2-dimethyl-3-propylbenzene1,2-dimethyl-4-propylbenzene- 1,3-dimethyl-2-propylbenzene,3-dirnethyl--propylbonzene dimethyl-5-propylben zene l 31,-dimethyl-2-propylbenzene l di-(l,2-dimethyl-3-nropyl-dimethyl-3-isopropylbenzene -dimethyl-4is0pr0pylbenzene,3-dirnethyl-2-isopropylben zene--.1,3-dimethyl-dsopropylbenzenel,3dimethy]-5-isopropylbenzene-1,-dirnethyl-2-isopropylbenzene n-amylhon 7P1! o pridsoamylbenzene. sec-isoainylb enzene tert-amylbenzene. C 11 aromatic fra ctidi-(p-methyl-isobutylphenyl) di-(o-methyl-tert-butylphenyl)-ethanesdi-(m-methyl-tert-butylphenyl)-ethanesdi-(p-methyl-tert-butylphenyl)-ethanesdi-(o-ethyl-n-propylphenyl)-ethanesdi-(m-ethyl-n-propylphenyl)-ethanesdi-(p-ethyl-n-propylphenyl)-ethanesdl-(oethyl-isopropylphenyl)-ethanesdi-(m-othyl-isopropylphenyl)-ethanesdi-(pethyl-isopropylphenyl)-etharesphenyD-ethanes (ii-(l,2-dimethyl-e-propylphenyl)cthanesdi-(l,3-diJnethyl-2-propylphenyl)-ethanesdi-(1,3-dimethyL4-propylphenyl)-ethanesdi(1,Z-dimethylbpropylphenyl)-ethanes. di(l,4-dimethyl-2-Dropylphdi-(1,2-dimethyl-3-isopropyl enyD-ethanes... phenyl)-ethanesdi(1,2-dimethylA-isopropylphenyl)-ethanesdi-(l,3-dimethyl-2-isopropylphenyl)ethanes di-(1,3-dimethyl-4-isopropyldi-(l,3-dimethyl-5-isopropylphenyl)-ethanesdi-(1,4-dimethyl-2'isopropylphenyl)ethanesdi- (n-amylphenyl) ethanesdi-(pri-isoamylphenyl)-ethancs dHsec-isoamylphenyl)-ethanesdi-(tort-amylphenyl)-ethanes til-(Ca alkylphenyD-ethanos pheny1)-ethanesC2 alkyl groups include ethyl-, and two methyl groups. b C; alkyl groupsinclude three methyl, methyland ethyl-, propyland isopropyl groups 04alkyl groups include two methyland one ethyl-, two ethyl, a methylandpropyl-, a methyland isopropyl-, n-butyl-, isobutyl-, tert-butyl groups.

4 Csalkyl groups include two ethyland one methyl-. ethyl-,

and one propyl-,

one ethyl-, and one isopropyl-, one methyland one n-butyl-, one

methyland one isobuty1-, one methyland one sec-butyl-, one methyland onetert-butyl-, one n-pentyl-, the several branched and unbranched primarypentyl-, the several isopentyls-, two secpentyls, tert-pentyl, andneopentyl groups.

In Example XI and in the examples of Table II, the alkyl benzenesemployed for illustrative purposes include alkyl substituted benzenesfor which: (a) the total number of carbon atoms of the alkyl group orgroups on the henzene is 1 to 5, but other alkyl groups containing 6 to13 While Table II and the tables hereinafter show examples of theposition isomers according to Formulae II and the hydrogenated productsaccording to Formula I, the tables are understood to also exemplify thepartial hydrogenated products according to Formulae VIII and IX; and itis further understood that there are exemplified herein the higherposition isomers (prepared by increasing the ratio of bridging compoundto the alkyl benzene compound in the reaction) according to Formulae Vand VI, and the hydrogenated products thereof according to Formulae IIand III, and also the partial hydrogenated products of Formulae V and VIand combinations of these.

The condensation of acetaldehyde with toluene of Example XI and thecondensation of the examples of Table 11 can alternately be carried outwith boron fluoride catalysts or with BF -phenol complex, BF -cthercomplex, BF -methanol complex, and the like BF catalysts. A preferredcatalyst is P 0 or polyphosphoric acids in H since these serve to removethe water of reaction according to the following reactions and thusmaintain constant concentration of the sulfuric acid:

H2804 CHZOHO 2CHaCuH5(toluene) carbon atoms likewise can be employed;(b) alkyl ben- 45 zenes with two different alkyl groups are substitutedon CHiCHwHimHi) H2O the benzene, but alkyl benzene with three differentalkyl groups substituted on the benzene likewise can be em- (2) 311,02113? ployed; (0) position isomer mixtures are prepared from a Singlealkyl 'benzena but the 'lmXmre of dlfierent alkyl 50 with such acatalyst higher production per unit weight of benzenes 01'10116 or morealkylbenzenes and benzene can H so is obtained likewise be employed toproduce a larger number of posi- 2 4 tion isomer precursors compoundsand their hydrogenated EXAMPLE XII products in which R and R of FormulaeI and IV are different alkyl substituents. 55 (a) Mixture of1,1-Di-(T0lyl) -Ethanes A 4-liter glass reaction vessel, cooled with anice/ Water bath, was charged with 1,196 grams toluene (13 moles), 14grams mercuric sulfate, and 257 grams of 97.4% sulfuric acid. Commercialacetylene from its pressure tank (containing acetone solvent tostabilize it) was bubbled through a water scrubber and sulfuric aciddrying chamber, and thence into the toluene-acid catalyst mixture,wherein the acetylene was rapidly absorbed and reacted. The rate ofacetylene addition was adjusted to maintain a reaction temperature notover about 15 C. Over a period of 10 hours about 4.50 moles (117 grams)acetylene were absorbed; During the absorption of the acetylene, thecolor of the mixture turned gradually to yellow, orange, red, *brown,and dark brown successively. Upon termination of the reaction, one literof water was added and after thorough mixing the acid layer wasseparated, the upper layer was again Washed with 1 liter of Waterfollowed by 1 liter of aqueous 3% sodium carbonate solution. Thehydrocarbon layer was then distilled from a Claisen flask. Following thetoluene removal by distillation, the product was distilled as follows:

Fractions B.P., J2 'ns Yield (g.)

mm. Hg

(b) Mixture of JJ-Di-(Methylcyclohexyl)-Ethanes Fraction 1, the1,1-di-(tolyl)-ethanes in quantity of 210 grams (1 mole) washydrogenated as in Example I, employing 41 grams of Raney nickelcatalyst (Girdler G-49 catalyst) and 800 grams of methylcyclohexane assolvent. The time of hydrogenation and maximum temperature were 3.5hours and 261 C. respectively. After removal of catalyst by filtrationand methylcyclohexane by distillation and almost a quantitative yield of1,1-di-(methylcyclohexyl)-ethane position isomers were obtained havingthe following properties: B.P. C.=1746/36 mm. Hg; M.P.=below 65 C.; D=0.891; N =L48l6; Gardner viscosity=50 centipoises -5 C. 'The elementalanalysis of this position isomer mixture or" 1,1-di-(methylcyclohexyl)ethane was carbon 86.65% and hydrogen 13.48% and thecombustion energy was 19,670 B.t.u./lb. (gross), 18,400 B.t.u./l=b.(net) and 136,710 Btu/gal. (net).

Alternatively, the acetylene can be preliminarily passed throughsulfuric acid-HgSO combination to convert it to acetaldehyde which isthen passed into sulfuric acidtoluene mixture. From a practicalstandpoint this method has the advantage of maintaining the life of theacid catalyst since the following scheme may be employed.

Step A:

Hg salt 1 mole acetylene 1 mole water W 1 mole acetaldehyde Step B:

H2SO4 1 mole acctaldehyde 2 moles toluene 1 mole 1,1-cli-(t01y1) ethane1 mole water As the sulfuric acid in step A becomes depleted in water,the acid in step B is becoming diluted. Thus when equal volumes of 97%sulfuric acid are used to start operations in both steps A and B thenthe acid in step A becomes 100% while the acid in step B talls to 94%the acids are exchanged and the process repeats itself. When the 94%sulfuric acid in step A builds up to 100% (by supplyin water to theacetylene to form acetaldehyde) and in step B when the 100% sulfuricacid is diluted to 94% (by removing water from the 'acetaldehyde) thenthe acids in the two steps can again be exchanged. The toluene, ofcourse, may be replaced by other alkyl benzenes as set forth in Table IIfollowing Example XI.

EXAMPLE XIII (a) Mixtures of 1,1-Di-(Tolyl)-Ethanes This exampleotherwise similar to Example XII illustrates the effect when highertemperatures are employed during the acetylene absorption and reaction;2.27 moles of acetylene were absorbed over a period of 3.75 hours at atemperature ranging from to 28 C. The yield of (a) 1,1-di-(tolyl)-ethaneposition isomers was 58% of theory based on acetylene reacted and ([2)higher condensation products accounted for the remainder of the yield(42%). The (a) fraction product was 214-244 C./90 mm. Hg; N =L5600 and D=0.976.

26 (b) Mixtures of 1 ,1 -Di (M ethylcycloh exyl -Ellzanes Hydrogenationof (a) according to the procedure of Example I yielded quantitatively1,1-di-(methylcyclohexyl)-methane position isomers with the followingproperties B.P.=167185 C./36 mm. Hg; M.P. ='below 65 C.; D =0.890; N=1.4895; viscosity=320 centipoises at -20 C. and the energy ofcombustion: 19,550 B.t.u./lb. (gross); 18,280 B.t.u./lb. (net); 135,640Btu/gallon (60 F.) (net).

In an alternative procedure under the same conditions, I can employ BFcomplexes with water or, alcohols or, phenols or, others or acids, etc.inthe presence of a mercuric compound such as mercuric oxide, mercuricacetate or sulfate, to replace the sulfuric acid of the abovepreparation. In this case, addition of a trace amount of water to thereaction mixture is helpful to initiate the reaction.

EXAMPLE XIV (a) Mixture of Ll-Di-(TolyD-Ethanes The procedure of ExampleXII was repeated using a mixture of ethylene and acetylene (ratio40/60). In this example 828 grams of toluene, (9 moles), 119 grams of97.3% sulfuric acid (1.28 moles), 7 grams HgSOL, (0.023 mole), and 0.465mole acetylene (12.1 g.) to gether with ethylene were reacted at atemperature of 4 to 6 C. in a reaction time of 2 hours. The reactionmixture was poured into 700 ml. water after the reaction was completed.The hydrocarbon layer was separated and washed free of acid anddistilled. The mixture of 1,1-di- (tolyl)-ethane position isomers wereobtained in 88% yield based on the acetylene absorbed. The propertiesthereof were: B.P.=115123 C./1 mm. Hg, and N =1.5 665.

(b) Mixtures of 1,1-Di-(Methylcyclohexyl)-Ethanes Hydrogenation of theposition isomers of this 1,1-di- (tOlyD-ethane as in Example XII yieldeda. similar high energy fuel comprising a mixture of the position isomersof 1, l-di- (methylcyclohexyl) -ethanes.

EXAMPLE XIV-A (a) M'ixture of 1,1-Di- (Ethylmethylphenyl) -Ethanes Theprocedure of Example XIV was repeated employing 368 grams (4 moles) oftoluene, 408 grams (4 moles) of 97% sulfuric acid, 68 grams (1 mole) ofboron fluoride and in a pressure vessel was added 112 grams (4 moles) ofethylene (as in Example VIII-A) and after the ethylene reacted then 26grams (1 mole) of acetylene was gradually added and reacted;- ;Theproduct was recovered (as in Example XIV) yielding principally a mixtureof position isomers of 1,l-di-(ethylmethylphenyl)- ethanes.

(b) Mixture of 1,1 -D1'-(Ethylmethylcyclolzexyl) -Ethanes The1,1-di-(ethylmethylphenyl)- thanes of (a) above was hydrogenatedaccording to Example XII (b) and the recovered product was principally amixture of position isomers of 1,1-di-'(ethylmethylcyclohexyl)-ethaneswhich had a net fuel value greater than 135,000 B.t.u./ gallon.

EXAMPLE XV (a) Mixture of 1,1-Di-(T0lyl)-Ethanes Example XIV wasrepeated, but omitting the ethylene from the feed. The results weresimilar. From 11.1 g. of acetylene a yield of 1,1-di-(tolyl)-ethanesresulted having N =1.5650; D =0.98l; M.P.= below -65 C.; and aviscosity=50 poises -25 C.

(b) Mixture of 1,1-Di-(Methylcyclohexyl)-Ethanes Hydrogenation of 84 g.of this product was conducted at -180 C. with 700 to 1100 p.s.i.hydrogen over Raney nickel (16.8 g.) as the catalyst for a 6 hourperiod. About 90% yield of a mixture of position isomers of 1,1-di-(methylcyclohexyl)-ethane resulted after filtering the product anddistilling to remove methylcyclohexane solvent and without furtherfractionation, the product had the following properties: D :0.891; N=-1.48l5; C. and energy of combustion=19,825 B.t.u./lb. (gross); 18,555Btu/lb. (net); 137,865 Btu/gallon (net).

EXAMPLE XVI (a) Mixture of 1,1-Di-(Xylyl)-Ethanes In this example 1378grams (13 moles) of mixed xylenes (Xylene fraction of same compositionas set forth in Example VI) was reacted with 104 grams of acetylene(freed of acetone) in the presence of 257 grams 97.4% sulfuric acid and14 grams HgSO over a period of 7 hours at 5 to 20 C. A 57% yield wasobtained of a mixture of l,1-di-(xylyl)-ethanes,1,1-di(ethylphenyl)-ethanes and l- (xylyl)-l-(ethylphenyl)-ethanescontaining small amounts of analogous components containing the tolylsubstituents. The properties of the l,l-di-(xylyl)-ethanes were: B.P.=136160 C./4 mm. Hg, N =1.5665.

(b) Mixture of 1,1-Di-(Dimethylcyclohexyl)-Ethanes In this Example XVI amaterial, 238 grams (one mole) in 800 grams methylcyc-lohexane washydrogenated over Raney nickel (48 grams) according to the procedures ofExample I, at 1000 to 1300 p.s.i. hydrogen pressure and in thetemperature range 140 to 214 C. for 6 hours. The recovered high energyfuel (95% yield) had the following properties: B.P.=136141 Cat 2 mm. Hg,M.P. below 70 C., D =0.893, N =l.4845, viscosity: 50 centipoises 20 C.or 98.5 poises -30 C.

The elemental analysis was 86.90% carbon and 13.52% hydrogen and theenergy of combustion was 19,715 B.t.u./lb. (gross), 18,440 B.t.u./lb.(net), 137,285 Btu/gallon (net).

EXAMPLE XVII (a) Mixtures of 1,2-Di-(Tlyl) -Ethanes The procedure ofExample XI was repeated substituting ethylene glycol for theacetaldehyde. In this example, 1244 grams (13.5 moles) of toluene wascombined with 609 grams (6 moles) of 97.3% sulfuric acid as catalyst,and 186 grams (3 moles) of ethylene glycol were added over a period of 3hours, the mixture being maintained at 24 C. After addition wascomplete, the temperature of the mixture was raised to and maintained at40 C. for 1.5 hours; The acid layer was separated, the upper layer waswashed with 1 liter of water and then with 1 liter 1% soda ash solution.Distillation of the washed product removed the unreacted toluene andyielded di-(tolyl)- ethane position isomers having N =1.5371.

(b) Mixtures of 1,2-Di-(Methylcyclolzexyl) thanes The1,2-di-(tolyl)-ethanes were hydrogenated as in Example I to give a highenergy fuel of this invention, a mixture of the position isomers of1,2-di-(methylcyclohexyl) -ethanes.

EXAMPLE XVlII (a) Mixtures of 1,2-Di-(Isopropylphenyl)-Ethanes A 4-literglass vessel equipped with a condenser, agitator, thermometer andopening for addition of reactants was immersed in an ice bath and thefollowing reactants were added: 720 grams (6 moles) of cumene, 85 grams(1 mole) 1,2-dichloroethane. The temperature of the reactants wereallowed to fall to C. and 65 grams (0.5 mole) of freshly sublimedaluminum chloride added in increments over 15 minutes and hydrogenchloride fumes were given off. The mixture was allowed to standovernight with the temperature rising to room temperature as the ice inthe cooling bath melted. The. reaction mixture was added to 700 grams ofice and 30 ml. of concentrated hydrochloric acid and the mass hea.ed toreflux then cooled to 50 C. and the hydrocarbon layer 28 separated andWashed first'with 1 liter of 1% hydrochloric acid and then with 1 literof water and the unreacted cumene distilled off. The resultinghydrocarbon was principally a mixture of the position isomers of 1,2- i-(isopropylphenyl) -ethanes.

(b) Mixtures of 1,2-Di-(Isopropylcyclahexyl)-Ethanes The productcomprising 1,2-di-(isopropylphenyl)-ethanes was hydrogenated employingRaney nickel catalyst and methylcyclohexane as solvent according to theprocedure of Example I and the resulting fuel after removal of thecatalyst and the methycyclohexane was a mixture of position isomers of1,2-di-(isopropylcyclohexyl)-methtanes having a net fuel value greaterthan 135,000 B.t.u./ gallon.

Zn this Example XVIII, the 720 grams of cumene (which is a substantialexcess over that required for stoichiometric reaction with the1,2-dihalopropane) may be substituted by any of the alkyl benzenesemployed in Examples 1 to 12 and 14 to 70 of Table II and the di-(alkylphenyl)-ethanes formed are the same as those set forth in Table IIexcept that the ethane bridge is substituted in the 1,2-positionsinstead of the 1,1-position and these products are hydrogenated to yieldthe di-(alkylcyclohexyl)-ethanes except that the ethane bridge issubstituted in the 1,2-positions instead of the 1,1-position. In thejust set forth alternate examples, the alkyl benzene employed forillustrative purposes include alkyl substituted benzenes for which: (a)the total carbon count or" the alkyl group or groups on the benzene is 1to 5, but 6 to 13 carbon atoms containing alkyls on the alkyl benzeneslikewise can be employed; (b) alkyl benzenes with two different alkylgroups can be substituted on the henzene, but alkyl benzenes with threediiferent alkyl groups substituted on the benzene likewise can beemployed; (c) position isomer mixtures are prepared from a single alkylbenzene, but the mixture of different alkyl b'enzenes or one or morealkylbenzenes and benzene can likewise be employed to produce a largernumber of position isomer precursor compounds and their hydrogenatedproducts in which R and R of Formulae I and IV are different alkylsubstituents.

EXAMPLE XIX (a) Mixtures of 1,1-Di-(T0lyl)-Pr0panes In this example,1658 grams (18 moles) of toluene were condensed with 162.4 grams (2.8moles) of propionaldehyde, and 406 grams (4 moles) of 97.6% sulfuricacid was used as catalyst as in Example XI. The reaction was conductedin an agitated glass vessel cooled in an ice bath. The propionaldehydewas added dropwise over a period of minutes and the temperature of thereactants held at 6-10" C. On completion of addition of the aldehyde,the reaction was allowed to run another 25 minutes then the hydrocarbonlayer separated and washed free of acid and distilled. The yield of1,1-di- (tolyl)-propane position isomers was 144.5 grams (23% yield) andabout 68 grams of 1-tolyl)-propane (18% yield). The properties of the1,1-di-(tolyl) -propane position isomers were: B.P. 275-375 C. 760 mm.Hg, N =1.5310; D =0.958, F.P.:below -65 C.

(b) Mixture of 1 ,1 -D i- (114 ethy Icy cl ohexyl Propanes The recoveredmixed position of the reactants was 3-4 31 catalyst can vary theparticular position isomer relationship of the mixture.

While Table III and the tables herein after show examples of theposition isomers according to Formulae II and the hydrogenated productsaccording to Formula I, the tables are understood to also exemplify thepartial hydrogenated products according to Formulae VIII and IX; and itis further understood that there are exemplified herein the higherposition isomers (prepared by increasing the ratio of bridging compoundto the alkyl benzene compound in the reaction) according to Formulae Vand VI, and the hydrogenated products thereof according to Formulae IIand III, and also the. partial hydrogenated products of Formulae V andVI and combinations of these.

EXAMPLE XX (a) Mixture of Ll-Di-(X ylyD-Propanes Propionaldehyde wasreacted with xylenes (the commerical xylenes employed are described inExample VI). In this reaction 1698 grams (16 moles) of mixed xylenes(Sinclair Petrochemicals lnc.) were reacted with 169 grams (2.9 moles)of propionaldehyde employing 507.5 grams moles) of 97.4% sulfuric acidas catalyst. The glass reactor was cooled with ice and the temperatureC. during the period of 5.6 hours required for the propionaldehydeaddition and was 2 C. for the 0.9 hour of stirring thereafter. Afterremoval of excess xylenes by distillation about 50 grams of product wasobtained distilling between 165300 C. at 745 mm. Hg with refractiveindex N =1.5500, D =0.970, F.P.=-54 C. and a viscosity of 85 centipoisesat 35 C. A residue of grams dark solid remained. The main fractionrepresented a yield of 1.6 moles of 1,1-di-(xylyl)-propanes admixed with1,1-di- (ethylphenyl) -prop anes and 1(xylyl) -1- (ethylphenyl)propanes.

(b) Mixtures of 1,1-Di-(Dimethylcyclohexyl)-Propanes Hydrogenation of258 grams of the product of (a) above with the aid of 52 grams of Raneynickel catalyst (Girdler catalyst #G-49) at 200 to 236 C. with 800 .gamsmethylcyclohexane as solvent according to the procedure of Example Igave about 90% yield of hydrogenated fuel comprising:1,1-di-(dimethylcyclohexyl)- propanes mixed with1,l-di-(ethylcyclohexyl)-propanes and 1 (dimethylcyclohexyl) 1(ethylcyolohexyl)- propanes, containing the numerous position isomers ofeach of the total mixture having the following characteristics:B.P.=300400 C./745 mm. Hg, 'F.P.=below 65 C., Dl .907, N :1.4988,viscosity=0.5 poise 31 C., 148 poises at 25 C., and with an energy ofcombustion of 19,510 Btu/lb. (gross), 18,230 B.t.u./lb. (net), 137,825Btu/gallon (net).

EXAMPLE XXI (a) Mixture of LZ-Di-(XylyD-Propanes A 4 liter glass vesselequipped with a condensenagitator, thermometer and opening for additionof reactants was immersed in a C. water bath and the following reactantswere added: 848 grams (8 moles) of mixed xylenes, 120 grams (0.9 mole)of freshly sublimed aluminum chloride and over 2.5 hours 226 grams (2moles) of 51,2-dichloropropane was added dropwise. The temperature ofthe reactants remained at C. during addition of the 1,2-dichloropropane.The reaction vessel was removed from the water bath and heated with anelectric heating jacket at 37 C. and the temperature of the stirredreactants was 35 C. for 2.5 hours. The hydrocarbon reaction mixture wasdiluted with 1 liter of mixed xylenes and 50 ml. of concentratedhydrochloric acid and the mixture poured onto 2 kilos of ice and warmedto the reflux temperature and the hydrocarbon layer separated. Thehydrocarbon layer was washed with 1 liter of water containing 25 ml. ofconcentrated hydrochloric 32 acid and then washed twice again with 1liter of water and the excess xylenes removed by distillation atatmospheric pressure.

The hydrocarbon fuel product was distilled as follows.

x Residue.

Fractions 1 and 2 chiefly comprise isomers of monoxylylpropane whilefractions 3 and 4 contain the mixed position isomers of1,2-di-(xylyl)-propanes.

(b) Mixture of 1 ,2-D i- (Dimethy lcycloh'exane) -Pr0 pan as The1,2-di-(xylyl)-propanes were hydrogenated according to the method ofExample I to yield a position isomer mixture which had a net fuel valuegreater than 135,000 B.t.u./ gallon. V

Other mixtures of position isomers similar to those set forth inExamples 1 to 70 of Table III except that the propylene bridge issubstituted in the 1,2-position instead of the 1,1-position are preparedin the manner set forth in (a) and (b) above.

EXAMPLE XXII (a) Mixture of 2,2Di-(T0lyl)-Pr0panes A 4 liter glassvessel equipped with condenser, agitator,

thermometer and opening for addition of reactantswas immersed in a 20 C.water bath and the following reactants added: 368 grams (4 moles) oftoluene, 134 grams (1 mole) of freshly sublimed aluminum chloride andover a 2 hour period was added dropwise 113 grams (1 mole) of2,2-dichloropropane while agitating vigorously and then the temperaturewas raised to 35 C. and the reactants agitated for another 2 hours. Thereaction mixture was worked up as in example XXl only using half thequantity of materials. The resulting product was distilled to yield afuel comprising the position isomers of 2,2-di-(tolyl)-propane.

(b) Mixture of 2,2-Di-(Methylcyclohexyl)-Pr0panes The2.2-di-(-tolyl)-propane fractions were hydrogenated according to ExampleI to yield a fuel of mixed position isomers of2,2-di-(methylcyclohexyl)propane which had a net fuel value greater than135,000 B.t.u./ gallon and excellent thermal stability.

In this Example XXII, the 368 grams (4 moles) of toluene (which is asubstantial excess over that required for stoichiometric reaction withthe 2,2-dichloropropane) may be substituted by any of the alkyl benzenesemployed in Examples 1 to 7 0 of Table III except that the propylenebridge is substituted in the 2,2-position instead of the 1,1- positionand these products are hydrogenated to yield thedi-(alkylcyclohexyl)-propanes, except that the propane bridge issubstituted in the 2,2-position instead of the 1,1- position. In thejust set forth alternate examples, the alkyl benzene employed forillustrative purposes include alkyl substituted benzenes for which: (a)the total carbon count of the alkyl group or groups on the benzene is 1to 5, but 6 to 13 carbon atom content alkyl groups may be present in thealkyl benzenes likewise can be employed: (5) alkyl benzenes with twodifierent alkyl groups are substituted on the benzene, but alkylbenzenes with three different alkyl groups substituted on the benzenelikewise can be employed: (0) position isomer mixtures are prepared froma single alkyl benzene, but the mixture of number of position isomerprecursor compounds and their EXAMPLE XXIII (a) Mixtures ofDi-(Xylyl)-Propanes In this example, 1700 grams (16 moles) of mixedxylenes (toluene 2%, o-xylene 19%, m-xylene 48%, pxylene 10%,ethylbenzene 21%) were reacted in a manner similar to the procedure ofExample XI, with 232 grams (4 moles) of 1,2-propylene oxide instead ofparaformaldehyde, using 406 grams (5 moles) of 96.98% sulfuric acid. Thepropylene oxide was added dropwise over a 3 hour period to the stirringmixture of xylenes and sulfuric acid maintained at a temperature betweenand 11 C. in a glass reaction vessel cooled with an ice bath. Thereaction vessel was then heated and stirred for 2 hours, the temperatureremaining in the range 4052 C. During addition of the propylene oxide,the color changed to slight orange and then to purple, during theheating stage the color changed to deep orange.

The hydrocarbon layer was separated and Washed first with 1 liter ofwater, and then 1 liter of 3% sodium carbonate aqueous solution, thenagain with 1 liter of Water and the residual xylenes removed bydistillation.

The following fractions were obtained:

B.P., Yield Fractions 0.!745 N (grams) mm. Hg

(b) Mixtures of Di-(Dimethylcyclohexyl)-Propanes Fractions 2 to 5 werecombined and this mixed fraction containing the di-(xylyl)-propaneposition isomers. This mixed fraction when hydrogenated according to theprocedure of Example I yields a high energy fuel with a net energy ofcombustion greater than 135,000 Btu/gallon.

(c) Mixture of J,3-Di-(XylyZ)-Pr0panes The 4 moles of 1,2 propyleneoxide are substituted by 304 grams (4 moles) of propanediol-1,3 and thereaction carried out as in (a) above to pield the position isomers ofl,3-di-(xylyl)-propane.

(d) Mixture of I,3-Di-(Dimethylcyclolzexyl)-Pr0panes The mixtures ofl,3-di(xylyl)-propanes prepared according to (c) above was hydrogenatedas in (b) above to yield the position isomers of1,3-di-(dim-ethylcyclohexyl)-propanes which was a high energy fuel ofnet energy of combustion greater than 135,000'B.t.u./ga1lon.

Other mixtures of position isomers similar to those set forth inExamples 1 to 70 of Table III except that the propylene bridge issubstituted in the 1,3-position instead of the 1,1-position, areprepared in the manner set forth in (c) and (d) above.

EXAMPLE XXIV (a) Mixtures of 1,1-Di-(Tolyl)-Butanes Following theprocedure of Example XI, 1566 grams (17 moles) of toluene was reactedwith 288 grams (4 moles) of n-butyraldehyde employing 500 grams (5moles) of 96.7% sulfuric acid as catalyst. The aldehyde addition timewas 3.5 hours and the temperature of the reactants was maintained at 36C. by cooling the reaction vessel with an ice bath. After about 2 hoursof additional stirring at 2-3 C. the product was diluted with 1500 ml.water and worked up as in Example XI. The unreacted toluene containingsome butyraldehyde UX were removed by distillation and the followingfractions were obtained:

B.P., Yield Fractions 07745 N 11 (grams) mm. Hg

1 163-300 1. 4644-1. 4703 97. 8 320-365 1. 5228-1. 5469 312. 6 ResidueDark solid 23.3

(b) Mixtures of 1,l Di-(Methylcyclohexyl)-Butanes Of thisdi-(tolyl)-butane, 119 grams was hydrogenated, according to theprocedure of Example I, in 800 grams of methylcyclohexane with 24 gramsRaney type nickel catalyst (Girdler 49-A catalyst) at 100210 C. under1000 p.s.i. hydrogen pressure. The recovered product from thehydrogenation amounted to 144 grams which represents the positionisomers of 1,1-di-(methylcyclohexyl)-butane in substantiallyquantitative yield after consideration of handling losses.

The properties of this 1,l-di-(methylcyclohexyl)butane fraction was asfollows: B.P.=300330 C. at 745 mm. Hg, N =1.4798, D =0.884, F.P.=below65 C., viscosity=98.5 poises 25 C., and the energy of combustion 19,630B.t.u./lb. (gross), 18,350 B.t.u./lb. (net), 135,240 B.t.u./gallon(net).

Alternatively, anhydrous hydrofluoric acid was substituted for thesulfuric acid catalyst in the above procedure and a similar butdilferent position isomeric composition resulted for the finalhydrogenated fuel in comparison to the above fuel.

EXAMPLE XXV (a) Mixtures of 1,1-Di-(Xylyl)-Butanes The procedure ofExample X was employed to react butyraldehyde with 1910 grams (18 moles)of commercial xylene mixture composition given in Example VI, 137 grams(1.9 moles) of butyraldehyde were reacted in the presence of 96 grams (3moles) of methanol and 408 grams (4 moles) of 96.7% sulfuric acidcontaining 2.2 grams (0.01 mole) of ferrous sulfate. The aldehyde wasadded over a period of 45 minutes to the xylene-acid methanol mixturemaintained at 73 to 87 C. and stirring was continued 3 hours followed by15 minutes at 75 to 85 C. From the reaction mixture after freeing ofxylene by distillation, the following fractions were obtained:

Fractions B.P., C./ N Yield, 2 mm. Hg grams Dark solid 84. 0

Fraction 1 had zero bromine number and has the properties ofl-xylyl-butane. Fraction 2 is the desired 1,1-di-(xylyl)-butane and itsdensity (D was 0.922 and N =1.5248.

(b) Mixtures 0 Di- (Dimethylcyclohexyl) -Bzltalzes Hydrogenationaccording to the procedure of Example I was conducted on about grams offraction 2 above, employing 16.0 grams Raney type nickel catalyst (Gir-'dler G-49 catalyst) at a pressure of 1150 p.s.i. of hydrogen at 100l30C. After removal of the 800 grams of methycyclohexane solvent 62.1 gramsof the hydrogenated product consisting of the position isomers of 1,1-di-(dimethylcyclohexyl)-butane isomers in mixtures with1,1-di-(ethyl-cyclohexyl)-1 (ethylcyclohexyl) butanes were obtained withthe following physical properties: B.P.=300 to 355 C. at 760 mm. of Hg,N =1.4805, D. =0.875, viscosity=l48 poises at -25 C., and the energy ofcombustion was 19,505 B.t.u./lb. (gross), 18,220 B.t.u./lb. (net),132,915 B.t.uJgallon (net).

EXAMPLE XXVI (a) Mixtures of Di-(TolyD-Butanes In this example, theposition isomers of di-(to1yl) butanes were prepared by reactingbutadiene-1,3 with toluene. In a glass vessel fitted with a stirrer andcooled in a salt-ice bath having a temperature of -6 to 9 C. 'wascharged 2211 grams (24 moles) of toluene and 406 grams (4 moles) of96.9% sulfuric acid. Over a period of 35 minutes a slow stream of cooledbutadiene gas was introduced under the surface of the agitatingtoluenesulfuric acid mixture. The butadiene gas flow (about 60 gramscharged) over a 2.5 hour period was adjusted so that the temperature ofthe reaction mixture was held at -2 C. and during the reaction the colorchanged from green to orange. The hydrocarbon layer was decanted fromthe reaction mixture and washed with 1 liter of Water followed by 1liter of 3% sodium carbonate aqueous solution and washed again with 1liter water and the toluene was distilled 05. The reaction products weredistilled yielding the following fractions:

In this reaction are obtained position isomers of (a) tolyl-butane, (b)tolyl-dibutane, (c) di-(tOIyD-butane, (d)'(methyl-butenyl-phenyl-(tolyl)-butane and (e) di(tolyl)-butyl-(tolyl)-butane. It is believed that the fractions boiling between200 and 300 C. contain position isomers of type set forth under (a) and(b) above; the fraction boiling between 360 and 405 C. contains isomersof the type set forth under (d) and (e) above.

([2) Mixtures of 1,1-Di(Methylcyclhexyl)-Butanes Hydrogenation offractions 1 to 12 of Example XXVI (a) combined, in Example I, gave amixture containing position isomers of di-(methylcyclohexyl)-butane,which as a fuel has a net energy of combustion greater than 135,000B.t.u./ gallon (net).

In place of the 60 grams of butadiene of this example or the 288 gramsof n-butyraldehyde of Example XXV, the following bridging compounds canbesubstituted: butadiene-1,2 (allene); the mono-unsaturated C alcoholssuch as 1-butenol-3 (methylvinyl-carbinol); or l-butenol- 4(allylcarbinol); or the C acetylenes such as 1-butine (ethylacetylene)Z-butine (dimethylacetylene); or the C diols such as 1,2-butyleneglycol, 1,3-butylene glycol, 1,4- butylene glycol, 2,3-butylene glycol,or 2,4-butylene glycol or the C, alkylene oxides such as 1,2-butyleneoxide or 2,3-butylene oxide and mixtures of these. If a Friedel- Craftscatalyst is employed in place of the Lewis acid, eg aluminum chloride,then the C dichlorides may be employed such as 1,1-dichlorobutane,2,2-dichlorobutane,

35 1,2-dichlorobutane, 1,-3-dichlorobutane, 1,4-dichlorobutane or2,3-dichlorobutane or even similar bromine or mixed chloro-bromine Ccompounds or mixtures of these.

EXAMPLE XXVII (a) Mixtures of Di-(T0lyl)-Pentane In this example, theprocedure of Example XXVI is followed except in place of the 60 grams ofbutadiene-1,3 there was added slowly 204 grams (3 moles) of piperyleneto the same quantity of toluene and acid and the reaction vessel wascooled with ice instead of salt and ice. The piperylene was added over a3 hour and 45 minute period with reaction temperature maintained at 2 C.and during the course of the reaction the color changed to dark orange.The hydrocarbon product layer was separated and freed of acid by waterwashing including an alkaline water wash and the residual tolueneremoved by distillation. The product was fractionated as follows:

Fractions B.P., 0.! N Yield (grams) mm. Hg

1 The kettle temperature was 400 C. 2 Fluid residue.

Fractions 1 and 2 were amber colored fluids and fraction 3 and 4 werenavy blue colored fluids and the undistillable residue was a viscousamber liquid.

Fractions 1 and 2 contained tolyl pentane and fractions 3 and 4contained di-(tolyl)-pentane and (pentenyl-tolyl)- (tolyl)-pentaneposition isomers.

(b) Mixtures of Di-(Methylcyclohexyl)-Pentanes Hydrogenation of theabove precursor fractions 3 and 4, as in Example I, gave a mixture ofposition isomers of di(methylcyclohexyl) pentane andmethyl-amylcyclohexyl-rnethyleyclohexyl-pentanes which as a fuel has anet energy of combustion greater than 135,000 B.t.u./ gallon.

In place of piperylene as the C diene bridging compound of this example,one can employ other aliphatic C dienes such as pentadiene-1,2,pentadiene-1,4-pentadiene- 2,3, isoprene; or the C -dienes and highersuch as hexadiene-l,2, hexadiene-1,3, hexadiene-1,4, hexadiene-1,5,hexadiene-1,6, hexadiene-2,3, hexadicne-2,4, hexadiene- 2,5,hexadiene-3,4, 2,3-dimethyl butadiene and other higher homologues ofthese dienes containing 7 to 13 carbon atoms. Further as bridgingcompounds in place of the piperylene can be employed aldehydes, diols,monounsaturated carbinols, alkylene oxides and in some instancesreactive saturated and unsaturated ketones having both branched andstraight chain C to C carbon skeleton and mixtures of these. IfFriedel-Crafts catalysts are used, then the middle dihalides containingchloroand/ or bromo-groups having C to C branched or unbranched carbonskeleton may be employed singly or as mixtures for bridging.

EXAMPLE XXVIII (a) Mixtures of (T 0lyl)-Undecenes To a 4 liter glassvessel equipped with a condenser, agitator and thermometer, placed inwater bath was added 685 grams (7 moles) of toluene, 102 grams (1 mole)of 96.19% sulfuric acid and during 1 hour and 15 minutes was addeddropwise 168 grams (1 mole) of undecylenic aldehyde and duringthisaddition of aldehyde the temperature of the reactants rose from 32 C. to41 C. Then was added dropwise an additional 50.7% grams (0.5 moles) of96.19% sulfuric acid over 1 hour and 15 minutes with the temperature ofthe reactants dropping to 33 C. The hydrocarbon layer was separated and37 washed with 1 liter of water, 1 liter of 3% aqueous solution ofsodium carbonate and 1 liter of water and the unreacted toluene removedby distillation. The product was distilled as follows:

Fractions B.P., O./ N 3 Yield (g.)

745 mm. Hg

383-393 1. 4819 18. 1 390-400 1. 4900 15. 3 400409 1. 5185 27. 1 ResidueCa. 30

(b) Mixtures of Position isomers of Di-(fl/Iethylcyclohexyl)-UndecaneHydrogenation of fractions 1 to 3 combined above according to theprocedure of Example I yields a high energy fuel comprising monoanddi-(methylcyclohexyl)- undecane position isomers having a combustionenergy greater than 135,000 B.t.u./ gallon (net).

EXAMPLE XXIX (a) Mixtures of 1,10-Di-(TZyI)-Decane To a liter glassvessel equipped with reflux condenser, stirrer and thermometer, andplaced in a water bath at 90 C. was added 552 grams (6 moles) of tolueneand 40 grams (0.3 mole) of freshly sublimed aluminum chloride and wasfurther added dropwise, 150 grams (0.5 mole) of decarnet ylenedibromide-Llt) (refractive index was N :l.4940) of over a period of 3hours with the temperature of the reactants remaining at 85 C. for thefirst 2 hours and rising to 93 C. during the third hour and then stirredat a temperature of about 90 C. for 2.5 hours. The reaction mixture waspoured into 650 grams of ice to which 65 m1. of 37% hydrochloric acidhad been added. The hydrocarbon layer was separated and washed with 300ml. of 6.2% aqueous solution of hydrochloric acid and dried by passingthrough a bed of sodium chloride.

Fractions B.P., 0.] ND Yield (g) mm. Hg

Residue dark oil.

Fraction 5 had a density of D =O.903 and fraction 6 a density of D=0.950 and these fractions contained the l,l0-di-(tolyl)-decane in amixture with lesser amounts of tolyl decane and di-(l0-tolyldecyl)-toluene isomers.

(b) Mixtures of 1,10-Di(Methylcycl0hexyl) -Decanes 38 ture of positionisomers of 1,10-di-(methylcyclohexyl)- decane mixed with smaller amountsof methylcyclohexyldecane anddi-(10-methylcyclohexyldecyl)-methylcyclohexane isomers, which mixturehad a net fuel Value greater than 135,000 B.t.u./ gallon.

The di-(alkylcyclohexyl)-alkane position isomer mixtures represented byFormula I are used as high energy fuels per se, but such fuels sometimesmay be mixed with other high energy hydrocarbon and non-hydrocarbonfuels in minor proportion. Thus the high energy liquid fuels of thisinvention can be employed in quantity at least in the order of 25% ormore to enhance the fuel value of presently used hydrocarbon fuels suchas kerosene, dialkyl cyclohexane, cumene, hydrogenated cumene,dl-(cumene), hydrogenated di-(cumene), paramenthane and the like; andthey can also be employed with such high energy fuels as boron hydride,decaborane, the alkyl boron hydrides, the trialkyl bor ons, and the liketo minimize fire and toxicity hazards inherent with these boronderivatives per se.

It has been found that by increasing the number of carbon atoms in thealkyl groups, even increasing the total number of carbon atoms in thecompound above the preferred range of 14 to 30 for a jet fuel liquidmixture, higher more viscous liquid and solids are produced still ofhigh energy content useful for fuels which need to be heated to reducetheir viscosity or to melt them for combustions as free flowing liquids.

These saturated compounds, including the partially hydrogenatedprecursor compounds have fuel uses also other than in jet fuels, and mayalso be used in other uses as stated above.

Thus compounds of the several Formulae I to III wherein R and R arealkyl radicals having 1 to 13 carbon atoms, and Y is an alkylene bridgehaving 1 to 13 carbon atoms, and m is an integer of 1 to 3 and n is aninteger from 1 to 4 and the total carbon atoms content of compoundsabove the range of 14 to 30 for example in the range of 30 to 54 areuseful fuels, and the higher hydrogenated compounds also are useful forless convenient fuel uses, as well as other uses. The intermediatepartially hydrogenated and non-hydrogenated compounds of Formulae IVthrough VI, and VIII through IX, are useful precursors for fuels byhydrogenation, and may be used as solid fuel hydrocarbons, which can bemelted for use as liquid fuel. They also can be burned as solid fuels.They may also be used as lubricants, heat transfer media, hydraulicfluids, plasticizers for elastomers and plastomers, adhesives, and likematerials in coatings, films or plastically formed articles.

The higher homologues and their isomers are produced by the same methodsemploying more or less molar proportions of the various reactants, asthe fuel and fuel precursor products of this invention, the bridgingcompounds employed are the same. It will be obvious to those skilled inthe art that minor modifications and changes may be made withoutdeparting from the essence of the invention. For example, while inliquid form, my products are outstandingly useful for high energy fuels,and can be burned as fuel for jet and other heat engines where the highenergy content is of advantage. It is therefore to be understood thatthe exemplary embodiments are illustrative and not restrictive to theinvention, the scope of which is defined iu the appended claims, andthat all modifications that come within the meaning and range ofequivalency of the claims are intended to be included therein.

I claim:

1. A high energy fuel consisting essentially of a mixture of positionisomers of at least three compounds having the formula:

erg H at wherein R and R are alkyl radicals each having from 1 J to 13carbon atoms and Y is an alkylene bridge having 1 to 13 carbon atoms, inis an integer from 1 to 3 and n is an integer from 1 to 4.

2. A high energy fuel consisting essentially of a mixture of positionisomers of at least three compounds having the formula:

wherein R and R are alkyl radicals each having from 1 to 4 carbon atomsand Y is an alkylene bridge having 1 to 13 carbon atoms, m is an integerfrom 1 to 3 and n is an integer from 1 to 4 and the total number ofcarbon atoms in the molecule is in the range of 14 to 30.

3. A high energy fuel consisting essentially of a mixture of positionisomers of at least three compounds having the formula:

mula:

' H at.

wherein R and R are lower alkyl radicals each having from 1 to 13 carbonatoms, Y is an alkylene bridge having 1 to 13 carbon atoms, In is aninteger from 1 to 3, and n is an integer from 1 to 4.

5. A composition of matter consisting essentially of a mixture of atleast three hydrocarbon position isomers having the formula:

wherein Y is an alkylene bridge having 1 to 13 carbon atoms.

6. A composition of matter according to claim 5 in which Y is amethylene radical.

7. A composition of matter according to claim 5 in which Y is anethylene radical.

8. A composition of matter consisting essentially of a mixture of atleast three hydrocarbon position isomers having the formula:

CzHs H YQCsHs wherein Y is an alkylene bridge having 1 to 13 carbonatoms. 9. A composition of matter according to claim 8 in which Y is amethylene radical.

10. A composition of matter consisting essentially of a mixture of atleast three hydrocarbon position isomers having the formula:

49 wherein Y is an alkylene bridge having 1 to 13 carbon atoms.

11. A composition of matter according to claim 10 in which Y is amethylene radical.

12. A composition of matter consisting essentially of a mixture of atleast three hydrocarbon position isomers having the formula:

0.11.9 H ygraat wherein Y is an alkylene radical having 1 to 13 carbonatoms.

13. A composition of matter according to claim 12 in which Y is amethylene radical.

14. A composition of matter consisting essentially of a mixture of atleast three position isomers having the formula:

wherein R and R are lower alkyl groups each having from 1 to 13 carbonatoms and Y is a divalent acyclic hydrocarbon bridge having 1 to 13carbon atoms, m is an integer from 1 to 3, n is an integer from 1 to 4.

15. A composition of matter consisting essentially of a mixture of atleast three position isomers of a substantially hydrogenated product ofa compound having the Formula 0:

wherein R and R are alkyl radicals each having from 1 to 13 carbon atomsand Y is a divalent acyclic hydrocarbon bridge having 1 to 13 carbonatoms, m is an integer from 1 to 3 and n is an integer from 1 to 4, saidhydrogenated compound containing from an intermediate quantity up to asmuch; hydrogen as a compound having the Formula b:

wherein the substituents R R and Y and the integers in and n of FormulaI) have the same significance as in Formula (1.

16. The process of operating a jet engine comprising burning a mixtureof at least three position isomers havin g the formula:

wherein R and R are alkyl radicals each having from 1 to 13 carbon atomsand Y is an alkylene bridge having 1 to 13 carbon atoms, in is aninteger'from 1 to 3 and n is an integer from 1 to 4 and the total numberof carbon atoms in the molecule is in the range of 14 to 30.

17. The process of forming a mixture of at least three position isomershaving the Formula a:

wherein R and R are alkyl radicals each having from 1 to 13 carbon atomsand Y is a divalent acyclic hydrocarbon bridge having 1 to 13 carbonatoms, m is an integer from 1 to 3, and n is an integer from 1 to 4,comprising

1. A HIGH ENERGY FUEL CONSISTING ESSENTIALLY OF A MIXTURE OF POSITIONISOMERS OF AT LEAST THREE COMPOUNDS HAVING THE FORMULA:
 16. THE PROCESSOF OPERATING A JET ENGINE COMPRISING BURNING A MIXTURE OF AT LEAST THREEPOSITION ISOMERS HAVING THE FORMULA: